2016.11.15
BZOJ1009:DP+矩阵乘法+KMP
BZOJ1898:矩阵乘法
BZOJ4101:贪心，考虑我们往右边撞的时候，我们会向左边冲
，于是枚举答案点利用一个指针计算即可！
2016.11.14
OI队内测试
2016.11.13
BZOJ4512：乱搞
BZOJ4102：DP+bfs
BZOJ4395：bfs
BZOJ3889：双键值最短路
BZOJ4512 #include <bits/stdc++.h> using namespace std; #define LL long long int N,sx,sy,ans; char s[1020]; bool vis[2020][2020],north[2020][2020],east[2010][2010]; int main(){ // freopen("data.in","r",stdin); // freopen("A.out","w",stdout); scanf("%d%s",&N,s); sx=sy=1010; for (int i=0;i<N;i++){ vis[sx][sy]=1; char ch=s[i]; if (ch=='N'){ sy++; if (!north[sx][sy-1]&&vis[sx][sy])ans++; north[sx][sy-1]=1; } if (ch=='S'){ sy--; if (!north[sx][sy]&&vis[sx][sy])ans++; north[sx][sy]=1; } if (ch=='E'){ sx++; if (!east[sx-1][sy]&&vis[sx][sy])ans++; east[sx-1][sy]=1; } if (ch=='W'){ sx--; if (!east[sx][sy]&&vis[sx][sy])ans++; east[sx][sy]=1; } } printf("%d ",ans); } BZOJ4102 #include<iostream> #include<algorithm> #include<cstring> #include<cstdio> #include<cmath> #include<queue> #define ll long long #define ld long double #define N 1005 #define M N*(N+1) using namespace std; int n,p,tot; int pre[M],v[M],now[N],f[N],dis[N][N]; bool vis[N]; queue<int>q; struct data{ int val,pos; }a[N]; int read() { int x=0,f=1; char ch; while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1; while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9'); return x*f; } void ins(int a,int b){++tot; pre[tot]=now[a]; now[a]=tot; v[tot]=b; } bool cmp(data a,data b){return a.val<b.val; } void bfs(int u) { memset(vis,0,sizeof(vis)); q.push(u); dis[u][u]=0; vis[u]=1; while (!q.empty()) { int x=q.front(); q.pop(); for (int p=now[x]; p; p=pre[p]) { int son=v[p]; if (!vis[son]) { dis[u][son]=dis[u][x]+1; q.push(son); vis[son]=1; } } } } int main() { n=read(); p=read(); for (int i=1; i<=n; i++) { int x=read(),d=read(); a[i].val=x; a[i].pos=i; for (int j=1; j<=d; j++) {int y=read(); ins(i,y); ins(y,i);} } for (int i=1; i<=n; i++) bfs(i); sort(a+1,a+n+1,cmp); for (int i=1; i<=n; i++) f[i]=a[i].val; for (int i=1; i<=n; i++) for (int j=1; j<=i-1; j++) { if (a[i].val>a[j].val && dis[a[i].pos][a[j].pos]) { f[i]=max(f[i],f[j]-dis[a[i].pos][a[j].pos]*p+a[i].val); } } int ans=0; for (int i=1; i<=n; i++) ans=max(ans,f[i]); printf("%d ",ans); return 0; } BZOJ4395 #include<iostream> #include<algorithm> #include<cstring> #include<cstdio> #include<cmath> #include<queue> #define ll long long #define ld long double #define N 205 #define M 40005 using namespace std; int dx[4]={0,0,1,-1},dy[4]={1,-1,0,0}; int pre[M],v[M],now[N*N],tot; int n,m,ans; queue<int>q; bool vis[N][N],lig[N][N]; int read() { int x=0,f=1; char ch; while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1; while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9'); return x*f; } int encode(int a,int b){return (a-1)*n+b; } void ins(int a,int b){ ++tot; pre[tot]=now[a]; now[a]=tot; v[tot]=b; } int main() { n=read(); m=read(); for (int i=1; i<=m; i++) { int a=read(),b=read(),c=read(),d=read(); ins(encode(a,b),encode(c,d)); } int last=1; ans=1; for (;;) { q.push(encode(1,1)); memset(vis,0,sizeof(vis)); vis[1][1]=1; lig[1][1]=1; while (!q.empty()) { int pp=q.front(),x,y; q.pop(); //last++; for (int p=now[pp]; p; p=pre[p]) { int son=v[p]; x=(son-1)/n+1,y=(son-1)%n+1; if (!lig[x][y]) lig[x][y]=1,ans++; } x=(pp-1)/n+1,y=(pp-1)%n+1; for (int i=0; i<4; i++) { int xx=x+dx[i],yy=y+dy[i]; if (xx<1 || xx>n || yy<1 || yy>n || !lig[xx][yy] || vis[xx][yy]) continue; vis[xx][yy]=1; q.push(encode(xx,yy)); } } if (last==ans) break; last=ans; } printf("%d ",ans); return 0; } BZOJ3889 #include<iostream> #include<algorithm> #include<cstring> #include<cstdio> #include<cmath> #include<queue> #define ll long long #define ld long double #define inf 100000000000000 #define N 1005 using namespace std; int s,t,m,n; ll a[N][N],b[N][N],dis[N],d[N]; int c[N]; bool vis[N]; queue<int>q; int read() { int x=0,f=1; char ch; while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1; while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9'); return x*f; } void spfa() { for (int i=1; i<=m; i++) dis[i]=inf; dis[s]=d[s]=0; vis[s]=1; q.push(s); while (!q.empty()) { int x=q.front(); q.pop(); vis[x]=0; //cout<<" "<<x<<endl; for (int i=1; i<=m; i++) { // cout<<i<<" "<<dis[i]<<" "<<dis[x]<<" "<<a[x][i]<<endl; if (dis[i]>dis[x]+a[x][i] || ((dis[i]==dis[x]+a[x][i]) && d[i]>d[x]+b[x][i])) { // cout<<" "<<x<<" "<<i<<" "<<a[x][i]+dis[x]<<endl; dis[i]=dis[x]+a[x][i]; d[i]=d[x]+b[x][i]; if (!vis[i]) vis[i]=1,q.push(i); } } //|| (dis[i]==dis[x]+a[x][i] && d[i]>d[x]+b[x][i]) } } int main() { s=read(); t=read(); n=read(); for (int i=1; i<=1000; i++) for (int j=1; j<=1000; j++) a[i][j]=inf; for (int i=1; i<=n; i++) { int len=read(),cnt=read(); for (int j=1; j<=cnt; j++) c[j]=read(),m=max(m,c[j]); for (int j=1; j<=cnt; j++) for (int k=j+1; k<=cnt; k++) if (a[c[j]][c[k]]>len || ((a[c[j]][c[k]]==len) && (b[c[j]][c[k]]>(k-j)))) a[c[j]][c[k]]=len,b[c[j]][c[k]]=k-j; } spfa(); if (dis[t]==inf) dis[t]=-1,d[t]=-1; cout<<dis[t]<<" "<<d[t]<<endl; return 0; }
2016.11.12
BZOJ3887: spfa（正边一次+反边一次）
BZOJ3886：状态压缩dp+二分（f[i]表示看电影状态为i的最长连续时间）
BZOJ4098：DP优化（f[i][j][k][l]：（i+j）==（k+l） 优化为f[i][j][k]：（i+j)满足滚动数组
BZOJ3888：把时间求出来+线段树
BZOJ3887 #include<algorithm> #include<iostream> #include<cstring> #include<cstdio> #include<cmath> #include<queue> #define N 100005 #define M 200005 using namespace std; int read() { int x=0,f=1; char ch; while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1; while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9'); return x*f; } int n,m; int a[N],b[N]; int tot,pre[M],v[M],now[N]; int bel[N],low[N],dfn[N],num[N],total,ind,top,z[N]; int dist1[N],dist2[N]; bool inq[N],vis[N]; queue<int> q; void ins(int a,int b){++tot; pre[tot]=now[a]; now[a]=tot; v[tot]=b;} void tarjan(int x) { low[x]=dfn[x]=++ind; ++top; z[top]=x; inq[x]=1; for (int p=now[x]; p; p=pre[p]) { int son=v[p]; if (!dfn[son]) tarjan(son),low[x]=min(low[x],low[son]); else if (inq[son]) low[x]=min(low[x],dfn[son]); } if (low[x]==dfn[x]) { ++total; num[total]=1; inq[x]=0; bel[x]=total; while (z[top]!=x) { int son=z[top]; bel[son]=total; inq[son]=0; num[total]++; top--; } top--; } } void build(int X) { memset(now,0,sizeof(now)); tot=0; for (int i=1; i<=m; i++) { int x=a[i],y=b[i]; if (bel[x]!=bel[y]) { if (X==1) ins(bel[x],bel[y]); else ins(bel[y],bel[x]); } } } void spfa1() { vis[bel[1]]=1; dist1[bel[1]]=num[bel[1]]; q.push(bel[1]); while (!q.empty()) { int x=q.front(); q.pop(); vis[x]=0; for (int p=now[x]; p; p=pre[p]) { int son=v[p]; if (dist1[son]<dist1[x]+num[son]) { dist1[son]=dist1[x]+num[son]; if (!vis[son]) q.push(son),vis[son]=1; } } } } void spfa2() { vis[bel[1]]=1; dist2[bel[1]]=num[bel[1]]; q.push(bel[1]); while (!q.empty()) { int x=q.front(); q.pop(); vis[x]=0; for (int p=now[x]; p; p=pre[p]) { int son=v[p]; if (dist2[son]<dist2[x]+num[son]) { dist2[son]=dist2[x]+num[son]; if (!vis[son]) q.push(son),vis[son]=1; } } } } int main() { n=read(); m=read(); for (int i=1; i<=m; i++) a[i]=read(),b[i]=read(),ins(a[i],b[i]); for (int i=1; i<=n; i++) if (!dfn[i]) tarjan(i); build(1); spfa1(); build(2); spfa2(); int ans=0; for (int i=1; i<=m; i++) if (bel[a[i]]!=bel[b[i]] && dist1[bel[b[i]]] && dist2[bel[a[i]]]) { ans=max(ans,dist1[bel[b[i]]]+dist2[bel[a[i]]]-num[bel[1]]); } printf("%d ",ans); return 0; } BZOJ3886 #include<iostream> #include<algorithm> #include<cstring> #include<cstdio> #include<cmath> using namespace std; int n,L; int num[25],len[25],c[25][1005]; int f[1100000]; int read() { int x=0,f=1; char ch; while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1; while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9'); return x*f; } int find(int x,int s) { int l=1,r=num[x],Ans=-1; while (l<=r) { int mid=(l+r)>>1; if (c[x][mid]<=s) Ans=mid,l=mid+1; else r=mid-1; } return Ans; } int main() { n=read(); L=read(); for (int i=1; i<=n; i++) { len[i]=read(); num[i]=read(); for (int j=1; j<=num[i]; j++) c[i][j]=read(); } f[0]=0; int s=1<<n,ans=0x7fffffff; for (int i=1; i<s; i++) f[i]=-1; for (int i=0; i<s; i++) { if (f[i]==-1) continue; int k=0; if (f[i]>L) { for (int j=i; j; j>>=1) if (j&1) k++; ans=min(ans,k); continue; } for (int j=1; j<=n; j++) { if (i&(1<<(j-1))) continue; int k=find(j,f[i]); if (k==-1) continue; f[i|(1<<(j-1))]=max(f[i|(1<<(j-1))],c[j][k]+len[j]); } } if (ans==0x7fffffff) ans=-1; printf("%d ",ans); return 0; } BZOJ4098 #include<iostream> #include<algorithm> #include<cstring> #include<cstdio> #include<cmath> #define N 505 #define mod 1000000007 #define add(a,b) (a=(a+b)%mod) using namespace std; int n,f[2][N][N]; char s[N][N]; int main() { scanf("%d",&n); for (int i=1; i<=n; i++) scanf("%s",s[i]+1); if(s[1][1]!=s[n][n]) { puts("0"); return 0; } int now=1,last=0; f[now][0][0]=1; for (int h=0; h<n; h++) { now^=1; last^=1; memset(f[now],0,sizeof(f[now])); for (int i=0; i<=h; i++) { int j=(h-i),a=i+1,b=j+1; for (int k=0; k<=h; k++) { int l=h-k,x=n-l,y=n-k; /* if (s[a+1][b]==s[x][y-1]) (f[now][i+1][k+1]+=f[last][i][k])%mod; if (s[a+1][b]==s[x-1][y]) (f[now][i+1][k]+=f[last][i][k])%mod; if (s[a][b+1]==s[x][y-1]) (f[now][i][k+1]+=f[last][i][k])%mod; if (s[a][b+1]==s[x-1][y]) (f[now][i][k]+=f[last][i][k])%mod; */ if(s[a+1][b]==s[x-1][y])add(f[now][i+1][ k ],f[last][i][k]); if(s[a+1][b]==s[x][y-1])add(f[now][i+1][k+1],f[last][i][k]); if(s[a][b+1]==s[x-1][y])add(f[now][ i ][ k ],f[last][i][k]); if(s[a][b+1]==s[x][y-1])add(f[now][ i ][k+1],f[last][i][k]); } } } int ans=0; for (int i=0; i<n; i++) add(ans,f[last][i][i]); printf("%d ",ans); return 0; } BZOJ3888 #include<iostream> #include<algorithm> #include<cstring> #include<cstdio> #include<cmath> #define N 50005 using namespace std; int n,tot; struct data{ int h,l,r; }a[N]; int b[2*N],cov[N*8]; int read() { int x=0,f=1; char ch; while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1; while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9'); return x*f; } bool cmp2(data a,data b){return a.h<b.h; } int get(int x,int c) { return x>=0?0:-x*c; } int cover(int k,int l,int r,int x,int y) { if (cov[k]) return 0; if (x<=l && r<=y) { cov[k]=1; return 1; } bool ret=0; int mid=(l+r)>>1; if (x<=mid) ret|=cover(k*2,l,mid,x,y); if (mid<y) ret|=cover(k*2+1,mid+1,r,x,y); cov[k]=cov[k*2]&cov[k*2+1]; return ret; } int find(int x) { int l=1,r=tot,ans=0; while (l<=r) { int mid=(l+r)>>1; if (b[mid]<=x) ans=mid,l=mid+1; else r=mid-1; } return ans; } int main() { n=read(); for (int i=1; i<=n; i++) { int x=read(),y=read(),c=read(); int l=get(x+1,c),r=get(x,c); a[i].l=l,a[i].r=r,a[i].h=y; b[++tot]=l; b[++tot]=r; } sort(b+1,b+tot+1); for (int i=1; i<=n; i++) a[i].l=find(a[i].l),a[i].r=find(a[i].r)-1; sort(a+1,a+n+1,cmp2); int ans=0; for (int i=1; i<=n; i++) ans+=cover(1,1,tot,a[i].l,a[i].r); printf("%d ",ans); return 0; }
2016.11.11
BZOJ4396 ：贪心
BZOJ4397 ：前缀和
BZOJ3943 ：最小生成树
BZOJ4576：DP：这道题还可以网上有很多种写法
BZOJ4582：DP：之前看错题想了好久最后发现题目意思 好水
BZOJ4412：贪心：这道题也不错，我们首先将每个数减1，如果存在j-->x的子段和大于0，
则说明一定有牛走出去，而我们可以知道在顺时针方向一定存在一个
点没有牛越过去，于是我们找到那个点将环转化为链即可，而这个点
一定是最大子段和的左节点，于是问题解决
2016.11.10
BZOJ1592 Usaco2008 Feb]Making the Grade 路面修整：离散+DP
BZOJ1051 HAOI 受欢迎的牛 ：tarjan
BZOJ2442 修建草坪 ：单调队列优化DP
BZOJ3890 Meeting time : 分层DP
BZOJ4390 Max Flow ：树上差分
BZOJ4525 ：二分答案判定
BZOJ4511 ：DP
1 BZOJ1592 2 3 #include<iostream> 4 #include<algorithm> 5 #include<cstring> 6 #include<cstdio> 7 #include<cmath> 8 #define N 3005 9 #define inf 0x7fffffff 10 using namespace std; 11 int n,m,ans,a[N],c[N],f[N][N]; 12 int read() 13 { 14 int x=0,f=1; char ch; 15 while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1; 16 while (x=x*10+ch-'0',ch=getchar(),ch>='0' && ch<='9'); 17 return x*f; 18 } 19 void solve() 20 { 21 sort(c+1,c+n+1); 22 m=unique(c+1,c+n+1)-(c+1); 23 for (int i=1; i<=n; i++) f[i][0]=inf/2; 24 for (int i=1; i<=n; i++) 25 { 26 for (int j=1; j<=m; j++) 27 { 28 f[i][j]=min(f[i-1][j]+abs(a[i]-c[j]),f[i][j-1]); 29 } 30 } 31 ans=f[n][m]; 32 for (int i=1; i<=n; i++) f[i][m+1]=inf/2; 33 for (int i=1; i<=n; i++) 34 { 35 for (int j=m; j>=1; j--) 36 { 37 f[i][j]=min(f[i-1][j]+abs(a[i]-c[j]),f[i][j+1]); 38 } 39 } 40 ans=min(ans,f[n][1]); 41 } 42 int main() 43 { 44 n=read(); 45 for (int i=1; i<=n; i++) c[i]=a[i]=read(); 46 solve(); 47 printf("%d ",ans); 48 return 0; 49 } 50 51 BZOJ1051 52 53 #include<iostream> 54 #include<cstring> 55 #include<algorithm> 56 #include<cmath> 57 #include<cstdio> 58 #define ll long long 59 #define N 10005 60 #define M 50005 61 using namespace std; 62 int n,m,ans,u[M],V[M]; 63 int now[N],pre[M],v[M],tot; 64 int ind,top,total,z[N],dfn[N],low[N],num[N],in[N],out[N],belong[N]; 65 bool vis[N],inq[N]; 66 int read() 67 { 68 int x=0,f=1; char ch; 69 while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1; 70 while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9'); 71 return x*f; 72 } 73 void ins(int a,int b){ 74 ++tot; pre[tot]=now[a]; now[a]=tot; v[tot]=b; 75 } 76 void dfs(int x) 77 { 78 79 dfn[x]=low[x]=++ind; 80 vis[x]=inq[x]=1; z[++top]=x; 81 for (int p=now[x]; p; p=pre[p]) 82 { 83 int son=v[p]; 84 if (!dfn[son]) {dfs(son); low[x]=min(low[x],low[son]);} 85 else if (inq[son]) low[x]=min(low[x],dfn[son]); 86 } 87 if (low[x]==dfn[x]) 88 { 89 ++total; 90 belong[x]=total; inq[x]=0; num[total]=1; 91 while (z[top]!=x) 92 { 93 int son=z[top]; 94 belong[son]=total; inq[son]=0; num[total]++; 95 top--; 96 } 97 top--; 98 } 99 } 100 int main() 101 { 102 n=read(); m=read(); 103 for (int i=1; i<=m; i++) 104 { 105 int x=read(),y=read(); 106 u[i]=x; V[i]=y; 107 ins(x,y); 108 } 109 for (int i=1; i<=n; i++) if (!dfn[i]) dfs(i); 110 for (int i=1; i<=m; i++) if (belong[u[i]]!=belong[V[i]]) 111 { 112 // cout<<" "<<belong[u[i]]<<" "<<belong[V[i]]<<endl; 113 ++out[belong[u[i]]]; ++in[belong[V[i]]]; 114 } 115 // for (int i=1; i<=total; i++) cout<<num[i]<<endl; 116 int sum=0; 117 for (int i=1; i<=total; i++) 118 { 119 if (!out[i]) {ans=num[i]; sum++; if (sum>=2) break;} 120 } 121 // cout<<ans<<endl; 122 if (sum>1) ans=0; printf("%d ",ans); 123 return 0; 124 } 125 126 BZOJ 2442 127 128 #include<iostream> 129 #include<cstring> 130 #include<algorithm> 131 #include<cmath> 132 #include<cstdio> 133 #define ll long long 134 #define N 100005 135 using namespace std; 136 int n,k,head,tail; 137 ll ans,sum,f[N]; 138 int a[N],pos[N]; 139 int read() 140 { 141 int x=0,f=1; char ch; 142 while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1; 143 while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9'); 144 return x*f; 145 } 146 int main() 147 { 148 n=read(); k=read(); 149 for (int i=1; i<=n; i++) a[i]=read(),sum+=a[i]; 150 for (int i=1; i<=n; i++) 151 { 152 while (head<=tail && pos[head]<i-k-1) head++; 153 f[i]=f[pos[head]]+a[i]; 154 while (head<=tail && f[pos[tail]]>=f[i]) tail--; 155 ++tail; pos[tail]=i; 156 } 157 ans=100000000000000; 158 for (int i=n-k; i<=n; i++) ans=min(ans,f[i]); 159 printf("%lld ",sum-ans); 160 return 0; 161 } 162 163 BZOJ3890 164 165 #include<iostream> 166 #include<cstring> 167 #include<algorithm> 168 #include<cmath> 169 #include<cstdio> 170 #define N 105 171 #define M (N*(N+1)) 172 #define ll long long 173 using namespace std; 174 int pre[M],v[M],val1[M],val2[M],now[N],n,m,tot; 175 bool f[N][M],g[N][M]; 176 int read() 177 { 178 int x=0,f=1; char ch; 179 while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1; 180 while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9'); 181 return x*f; 182 } 183 void ins(int a,int b,int c,int d) 184 { 185 ++tot; pre[tot]=now[a]; now[a]=tot; v[tot]=b; val1[tot]=c; val2[tot]=d; 186 } 187 int main() 188 { 189 n=read(); m=read(); 190 for (int i=1; i<=m; i++) 191 { 192 int u=read(),v=read(),a=read(),b=read(); 193 ins(u,v,a,b); 194 } 195 f[1][0]=g[1][0]=1; 196 for (int i=1; i<=n-1; i++) 197 { 198 for (int p=now[i]; p; p=pre[p]) 199 { 200 int son=v[p]; 201 for (int j=val1[p]; j<=10000; j++) f[son][j]|=f[i][j-val1[p]]; 202 for (int j=val2[p]; j<=10000; j++) g[son][j]|=g[i][j-val2[p]]; 203 } 204 } 205 bool bo=false; 206 for (int i=0; i<=10000; i++) 207 if (g[n][i] && f[n][i]) 208 { 209 bo=true; 210 printf("%d ",i); 211 break; 212 } 213 if (!bo) printf("IMPOSSIBLE "); 214 return 0; 215 } 216 217 BZOJ4390 218 219 #include<iostream> 220 #include<cstring> 221 #include<algorithm> 222 #include<cmath> 223 #include<cstdio> 224 #define N 60005 225 #define M N*2 226 #define ll long long 227 using namespace std; 228 int pre[M],v[M],now[N],tot,n,k,ans; 229 int f[N][25],bin[25],deep[N],val[N]; 230 int read() 231 { 232 int x=0,f=1; char ch; 233 while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1; 234 while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9'); 235 return x*f; 236 } 237 void ins(int a,int b){++tot; pre[tot]=now[a]; now[a]=tot; v[tot]=b; 238 } 239 void dfs(int x) 240 { 241 for (int i=1; i<=19 && bin[i]<=deep[x]; i++) f[x][i]=f[f[x][i-1]][i-1]; 242 for (int p=now[x]; p; p=pre[p]) 243 { 244 int son=v[p]; if (son==f[x][0]) continue; 245 deep[son]=deep[x]+1; f[son][0]=x; 246 dfs(son); 247 } 248 } 249 int lca(int x,int y) 250 { 251 if (deep[x]<deep[y]) swap(x,y); 252 int t=deep[x]-deep[y]; 253 for (int i=0; bin[i]<=t; i++) 254 { 255 if (t&bin[i]) x=f[x][i]; 256 } 257 for (int i=19; i>=0; i--) if (f[x][i]!=f[y][i]) x=f[x][i],y=f[y][i]; 258 if (x==y) return x; 259 return f[x][0]; 260 } 261 void dfs2(int x,int fa) 262 { 263 for (int p=now[x]; p; p=pre[p]) 264 { 265 int son=v[p]; if (son==fa) continue; 266 dfs2(son,x); val[x]+=val[son]; 267 } 268 ans=max(ans,val[x]); 269 } 270 int main() 271 { 272 n=read(); k=read(); 273 for (int i=1; i<n; i++) 274 { 275 int x=read(),y=read(); 276 ins(x,y); ins(y,x); 277 } 278 bin[0]=1; for (int i=1; i<=20; i++) bin[i]=bin[i-1]*2; 279 deep[1]=1; dfs(1); 280 for (int i=1; i<=k; i++) 281 { 282 int x=read(),y=read(); 283 int t=lca(x,y); 284 val[x]++; val[y]++; val[t]--; val[f[t][0]]--; 285 } 286 dfs2(1,0); 287 printf("%d ",ans); 288 return 0; 289 } 290 291 292 BZOJ4525 293 294 #include<iostream> 295 #include<cstring> 296 #include<algorithm> 297 #include<cmath> 298 #include<cstdio> 299 #define ll long long 300 #define inf 0x7ffffff 301 using namespace std; 302 int n,k,ans; 303 int a[50005]; 304 int read() 305 { 306 int x=0,f=1; char ch; 307 while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1; 308 while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9'); 309 return x*f; 310 } 311 bool pd(int mid) 312 { 313 int l=0; 314 for (int i=1; i<=k; i++) 315 { 316 int pos=a[l+1]; 317 while (l+1<=n && ((a[l+1]-pos)<=2*mid)) l++; 318 } 319 if (l>=n) return true; 320 return false; 321 } 322 int main() 323 { 324 n=read(); k=read(); 325 for (int i=1; i<=n; i++) a[i]=read(); 326 sort(a+1,a+n+1); 327 int l=0,r=inf-2; 328 while (l<=r) 329 { 330 int mid=(l+r)>>1; 331 if (pd(mid)) ans=mid,r=mid-1; else l=mid+1; 332 } 333 printf("%d ",ans); 334 return 0; 335 } 336 337 BZOJ4511 338 339 340 #include<iostream> 341 #include<cstring> 342 #include<algorithm> 343 #include<cmath> 344 #include<cstdio> 345 #define ll long long 346 #define N 50005 347 using namespace std; 348 int ans,n,a[N],f[N][8]; 349 int read() 350 { 351 int x=0,f=1; char ch; 352 while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1; 353 while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9'); 354 return x*f; 355 } 356 int main() 357 { 358 n=read(); 359 for (int i=1; i<=n; i++) a[i]=read()%7; 360 memset(f,-1,sizeof(f)); 361 f[0][0]=0; for (int i=1; i<=n; i++) f[i][a[i]]=1; 362 for (int i=1; i<=n; i++) 363 for (int j=0; j<=6; j++) 364 if (f[i-1][j]!=-1) f[i][(j+a[i])%7]=max(f[i][(j+a[i])%7],f[i-1][j]+1); 365 for (int i=1; i<=n; i++) ans=max(ans,f[i][0]); 366 printf("%d ",ans); 367 return 0; 368 }
2016.11.9
BZOJ1711： 最大流
BZOJ1642: 排序+DP
1 BZOJ1711 2 3 #include<iostream> 4 #include<cstring> 5 #include<algorithm> 6 #include<cmath> 7 #include<cstdio> 8 #include<queue> 9 #define inf 0x7fffffff 10 #define ll long long 11 #define N 505 12 #define M 50005 13 using namespace std; 14 int n,F,D,head,tail,list[N<<2],tot=1,S,T,ans=0; 15 int pre[M],v[M],cap[M],now[N],deep[N]; 16 queue<int>q; 17 int read() 18 { 19 int x=0,f=1; char ch; 20 while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1; 21 while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9'); 22 return x*f; 23 } 24 void ins(int a,int b,int c){ 25 ++tot; pre[tot]=now[a]; now[a]=tot; v[tot]=b; cap[tot]=c; 26 ++tot; pre[tot]=now[b]; now[b]=tot; v[tot]=a; cap[tot]=0; 27 } 28 void init_build() 29 { 30 n=read(); F=read(); D=read(); 31 S=0; T=n*2+F+D+1; 32 for (int i=1; i<=F; i++) ins(S,i,1); 33 for (int i=F+n*2+1; i<=F+n*2+D; i++) ins(i,T,1); 34 for (int i=1; i<=n; i++) 35 { 36 int A=read(),B=read(); 37 for (int j=1; j<=A; j++) {int x=read(); ins(x,F+i,1);} 38 for (int j=1; j<=B; j++) {int x=read(); ins(F+n+i,F+n*2+x,1);} 39 } 40 for (int i=1;i<=n;i++) ins(F+i,F+i+n,1); 41 } 42 bool bfs() 43 { 44 for (int i=S;i<=T;i++) deep[i]=-1; 45 deep[S]=0; head=0,tail=1,list[1]=S; 46 while (head<tail) 47 { 48 int x=list[++head]; 49 for (int p=now[x]; p; p=pre[p]) 50 { 51 int son=v[p]; 52 if (cap[p] && deep[son]==-1) 53 { 54 deep[son]=deep[x]+1; 55 if (son==T) return 1; 56 list[++tail]=son; 57 } 58 } 59 } 60 return 0; 61 } 62 int find(int x,int tmpflow) 63 { 64 int temp,re; 65 if (x==T) return tmpflow; 66 re=temp=0; 67 for (int p=now[x]; p; p=pre[p]) 68 { 69 int son=v[p]; 70 if (cap[p] && deep[son]==deep[x]+1) 71 { 72 temp=find(son,min(tmpflow,cap[p])); 73 cap[p]-=temp; 74 cap[p^1]+=temp; 75 re+=temp; 76 tmpflow-=temp; 77 if (tmpflow==0) break; 78 } 79 } 80 deep[x]=-1; 81 return re; 82 } 83 void dinic() 84 { 85 ans=0; 86 while (bfs()) 87 { 88 ans+=find(S,inf); 89 } 90 } 91 int main() 92 { 93 tot=1; 94 init_build(); 95 dinic(); 96 printf("%d ",ans); 97 return 0; 98 } 99 100 BZOJ 1642 101 102 #include<iostream> 103 #include<cstring> 104 #include<cmath> 105 #include<cstdio> 106 #include<algorithm> 107 using namespace std; 108 int n,m,r,ans=0; 109 int read(){ 110 int x=0,f=1; char ch; 111 while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1; 112 while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9'); 113 return x*f; 114 } 115 struct data{ 116 int l,r,val; 117 }a[1005]; 118 int f[1005]; 119 bool cmp(data a,data b) 120 { 121 return a.l==b.l?a.r<b.r:a.l<b.l; 122 } 123 int main() 124 { 125 n=read(); m=read()+1; r=read(); 126 a[1].l=a[1].r=-100; a[1].val=0; 127 for (int i=2; i<=m; i++) 128 { 129 a[i].l=read(),a[i].r=read()-1,a[i].val=read(); 130 } 131 sort(a+1,a+m+1,cmp); 132 for (int i=2; i<=m; i++) 133 { 134 for (int j=1; j<=i-1; j++) 135 { 136 if (a[j].r+r<a[i].l) 137 { 138 f[i]=max(f[i],f[j]+a[i].val); 139 ans=max(ans,f[i]); 140 } 141 } 142 } 143 printf("%d ",ans); 144 return 0; 145 }
2016.11.8
BZOJ1708：背包
BZOJ1690：01分数规划+spfa+二分
BZOJ1669：LIS问题+单调栈
1 BZOJ 1708 2 3 #include<iostream> 4 #include<cstring> 5 #include<algorithm> 6 #include<cmath> 7 #include<cstdio> 8 #define ll long long 9 using namespace std; 10 int n,m; 11 ll f[10005]; 12 int read() 13 { 14 int x=0,f=1; char ch; 15 while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1; 16 while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9'); 17 return x*f; 18 } 19 int main() 20 { 21 n=read(); m=read(); f[0]=1; 22 for (int i=1; i<=n; i++) 23 { 24 int x=read(); 25 for (int i=x; i<=m; i++) f[i]+=f[i-x]; 26 } 27 printf("%lld ",f[m]); 28 return 0; 29 } 30 31 32 BZOJ1690 33 #include<iostream> 34 #include<cstring> 35 #include<algorithm> 36 #include<cmath> 37 #include<cstdio> 38 #define ll long long 39 #define N 1005 40 #define M 5005 41 using namespace std; 42 int n,m,tot; 43 int a[N],now[N],pre[M],v[M]; 44 double ans,mid,val[M],value[N],dis[N]; 45 bool vis[N]; 46 int read() 47 { 48 int x=0,f=1; char ch; 49 while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1; 50 while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9'); 51 return x*f; 52 } 53 void ins(int a,int b,int c){++tot; pre[tot]=now[a]; now[a]=tot; v[tot]=b; val[tot]=c; 54 } 55 bool spfa(int x) 56 { 57 vis[x]=1; 58 for (int p=now[x]; p; p=pre[p]) 59 { 60 int son=v[p]; 61 if (dis[son]<dis[x]+value[son]-mid*val[p]) 62 { 63 if (!vis[son]) 64 { 65 dis[son]=dis[x]+value[son]-mid*val[p]; 66 if (spfa(son)) return 1; 67 } 68 else return 1; 69 } 70 } 71 return vis[x]=0; 72 } 73 int main() 74 { 75 n=read(); m=read(); 76 for (int i=1; i<=n; i++) value[i]=read(); 77 for (int i=1; i<=m; i++) 78 { 79 int a=read(),b=read(),c=read(); ins(a,b,c); 80 } 81 double l=0,r=1000,eps=1e-3; 82 while (r-l>eps) 83 { 84 memset(dis,254,sizeof(dis)); 85 memset(vis,0,sizeof(vis)); 86 mid=(l+r)/2.0; dis[1]=0.0; 87 if (spfa(1)) ans=mid,l=mid; else r=mid; 88 } 89 printf("%0.2lf ",ans); 90 return 0; 91 } 92 93 94 BZOJ1669 95 96 #include<iostream> 97 #include<cstring> 98 #include<algorithm> 99 #include<cmath> 100 #include<cstdio> 101 #define N 5005 102 #define ll long long 103 using namespace std; 104 int n,tot; 105 int b[N]; 106 int read() 107 { 108 int x=0,f=1; char ch; 109 while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1; 110 while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9'); 111 return x*f; 112 } 113 int main() 114 { 115 int n=read(),tot=0; 116 for (int i=1; i<=n; i++) 117 { 118 int x=read(); 119 if (x>b[tot]) 120 { 121 tot++; b[tot]=x; 122 } 123 else 124 { 125 int l=tot; 126 while (l>=1 && b[l]>=x) l--; 127 //cout<<" "<<l<<endl; 128 b[l+1]=x; 129 } 130 } 131 printf("%d ",tot); 132 return 0; 133 }
2016.11.7
BZOJ3298：打表找规律
BZOJ3296：并查集
BZOJ1599：模拟
BZOJ1232：最小生成树
1 BZOJ3298 2 3 4 #include<iostream> 5 #include<cstring> 6 #include<algorithm> 7 #include<cmath> 8 #include<cstdio> 9 #define ll long long 10 #define N 1000005 11 using namespace std; 12 int n,m,f[N]; 13 int read() 14 { 15 int x=0,f=1; char ch; 16 while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1; 17 while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9'); 18 return x*f; 19 } 20 int main() 21 { 22 n=read()+1; m=read()+1; 23 f[1]=1; int t=0; 24 for (int i=2; i<=m; i++) 25 { 26 if (f[i]) continue; 27 t++; f[i]=i+t; if (i+t<=m) f[i+t]=i; 28 } 29 int T=read(); 30 while (T--) 31 { 32 int x=read()+1,y=read()+1; 33 if (f[x]==y) printf("Farmer John "); else printf("Bessie "); 34 } 35 return 0; 36 } 37 38 39 BZOJ3296 40 41 #include<iostream> 42 #include<cstring> 43 #include<algorithm> 44 #include<cmath> 45 #include<cstdio> 46 #define ll long long 47 #define N 40005 48 using namespace std; 49 int fa[N],id[N],n,m,ans; 50 int read() 51 { 52 int x=0,f=1; char ch; 53 while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1; 54 while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9'); 55 return x*f; 56 } 57 int find(int x){return x==fa[x]?x:fa[x]=find(fa[x]); 58 } 59 int main() 60 { 61 n=read(); m=read(); 62 for (int i=1; i<=n; i++) fa[i]=i; 63 for (int i=1; i<=n; i++) 64 { 65 int k=read(); 66 for (int j=1; j<=k; j++){int x=read(); if (!id[x]) id[x]=i; else {fa[find(id[x])]=find(i); id[x]=i;}} 67 } 68 for (int i=1; i<=n; i++) if (find(i)==i) ans++; 69 printf("%d ",ans-1); 70 return 0; 71 } 72 73 74 BZOJ1599 75 76 #include<iostream> 77 #include<cstring> 78 #include<algorithm> 79 #include<cmath> 80 #include<cstdio> 81 #define ll long long 82 using namespace std; 83 int sum[105],ans; 84 int read() 85 { 86 int x=0,f=1; char ch; 87 while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1; 88 while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9'); 89 return x*f; 90 } 91 int main() 92 { 93 int a=read(),b=read(),c=read(); 94 for (int i=1; i<=a; i++) 95 for (int j=1; j<=b; j++) 96 for (int k=1; k<=c; k++) sum[i+j+k]++; 97 sum[0]=0; ans=0; for (int i=3; i<=a+b+c; i++) if (sum[i]>sum[ans]) ans=i; 98 printf("%d ",ans); 99 return 0; 100 } 101 102 103 BZOJ1232 104 105 #include<iostream> 106 #include<cstring> 107 #include<algorithm> 108 #include<cmath> 109 #include<cstdio> 110 #define ll long long 111 #define N 100005 112 using namespace std; 113 int n,m; 114 struct data{ 115 int u,v,val; 116 }a[N]; 117 int c[N],Min=0x7fffffff,ans=0,fa[N],cnt=0; 118 int read() 119 { 120 int x=0,f=1; char ch; 121 while (ch=getchar(),ch<'0'||ch>'9') if (ch=='-') f=-1; 122 while (x=x*10+ch-'0',ch=getchar(),ch>='0'&&ch<='9'); 123 return x*f; 124 } 125 bool cmp(data a,data b){return a.val<b.val; 126 } 127 int find(int x) {return x==fa[x]?x:fa[x]=find(fa[x]);} 128 int main() 129 { 130 n=read(); m=read(); 131 for (int i=1; i<=n; i++) fa[i]=i; 132 for (int i=1; i<=n; i++) c[i]=read(); 133 for (int i=1; i<=m; i++) a[i].u=read(),a[i].v=read(),a[i].val=read()*2+c[a[i].u]+c[a[i].v]; 134 sort(a+1,a+m+1,cmp); 135 for (int i=1; i<=m; i++) 136 { 137 int u=a[i].u,v=a[i].v,val=a[i].val; 138 int fu=find(u),fv=find(v); 139 if (fv!=fu) 140 { 141 fa[fv]=fu; Min=min(Min,min(c[u],c[v])); 142 ans+=val; cnt++; if (cnt==n-1) break; 143 } 144 } 145 printf("%d ",ans+Min); 146 return 0; 147 }