目录
·贪心
·二分三分
解析啥的以后会有的
·T2种树
·练习T1
·练习T2
·练习T3
·练习T4
·练习T5
·练习T6
·T3扩散
1 /* 2 problem:yibentong10000 3 date:2019/4/21 4 author:Lonely.Devil 5 */ 6 7 #include<iostream> 8 #include<cstdio> 9 #include<cstring> 10 #include<algorithm> 11 using namespace std; 12 const int maxn = 1e3+5; 13 struct node{ 14 int s,f,dif; 15 }; 16 node a[maxn]; 17 int n,ans; 18 inline void init(){ 19 cin>>n; 20 for(int i =1;i <= n;i++)scanf("%d%d",&a[i].s,&a[i].f); 21 } 22 inline bool cmp(node x,node y){ 23 return x.f < y.f; 24 } 25 int main(){ 26 init(); 27 sort(a+1,a+1+n,cmp); 28 ans = 1; 29 int tmp = a[1].f; 30 for(int i = 2;i <= n;i++) 31 if(a[i].s >= tmp){ 32 ans++; 33 tmp = a[i].f; 34 } 35 cout<<ans<<endl; 36 return 0; 37 }
1 /* 2 problem:yibentong10001 3 date:2019.4.21 4 author:Lonely.Devil 5 */ 6 7 #include<iostream> 8 #include<cstdio> 9 #include<cstring> 10 #include<algorithm> 11 using namespace std; 12 const int maxn = 3e4+5; 13 struct node{ 14 int b,e,t; 15 }a[maxn]; 16 int visit[maxn]; 17 int n,ans,h; 18 inline void init(){ 19 cin>>n; 20 cin>>h; 21 for(int i = 1;i <= h;i++) 22 scanf("%d%d%d",&a[i].b,&a[i].e,&a[i].t); 23 } 24 inline bool cmp(node x,node y){ 25 return x.e < y.e; 26 } 27 int main(){ 28 init(); 29 sort(a+1,a+1+h,cmp); 30 for(int i = 1;i <= h;i++){ 31 int cnt = 0; 32 for(int j = a[i].b;j <= a[i].e;j++) 33 cnt += visit[j]; 34 if(cnt >= a[i].t)continue; 35 for(int j = a[i].e;j >= a[i].b;j--) 36 if(!visit[j]){ 37 visit[j] = 1; 38 cnt++; 39 ans++; 40 if(cnt == a[i].t)break; 41 } 42 } 43 cout<<ans<<endl; 44 return 0; 45 }
1 /* 2 problem:yibentong10002 3 date:2019/4/21 4 author:Lonely.Devil 5 */ 6 7 #include<iostream> 8 #include<cstdio> 9 #include<cstring> 10 #include<algorithm> 11 #include<cmath> 12 using namespace std; 13 const int maxn = 25e3+5; 14 struct node{ 15 double head,tail; 16 }a[maxn]; 17 int n,l,w,T,cnt,ans; 18 inline bool cmp(node x,node y){ 19 return x.head < y.head; 20 } 21 inline void init(){ 22 cin>>n>>l>>w; 23 cnt = 0; 24 for(int i = 1,r,position;i <= n;i++){ 25 scanf("%d%d",&position,&r); 26 if(r <= w/2)continue; 27 cnt++; 28 double tmp = r*r-w*w/4.0; 29 a[cnt].head = position-sqrt(tmp); 30 a[cnt].tail = position+sqrt(tmp); 31 } 32 } 33 int main(){ 34 cin>>T; 35 while(T--){ 36 init(); 37 sort(a+1,a+1+cnt,cmp); 38 ans = 0; 39 double position = 0; 40 bool flag = false; 41 while(position < l){ 42 ans++; 43 double tmp = position; 44 for(int i = 1;a[i].head <= tmp && i <= cnt;i++) 45 if(position < a[i].tail) 46 position = a[i].tail; 47 if(position == tmp && position < l){ 48 puts("-1"); 49 flag = true; 50 break; 51 } 52 } 53 if(flag == false)cout<<ans<<endl; 54 } 55 return 0; 56 }
1 /* 2 problem:yibentong10003 3 date:2019/4/30 4 author:Lonely.Devil 5 */ 6 7 #include<iostream> 8 #include<cstdio> 9 #include<cstring> 10 #include<algorithm> 11 #include<cmath> 12 using namespace std; 13 const int maxn = 1e3+5; 14 struct node{ 15 int position,Min; 16 }p[maxn]; 17 int a[maxn],b[maxn],ans[maxn]; 18 int n; 19 inline void init(){ 20 cin>>n; 21 for(int i = 1;i <= n;i++)scanf("%d",&a[i]); 22 for(int i = 1;i <= n;i++)scanf("%d",&b[i]); 23 for(int i = 1;i <= n;i++){ 24 p[i].Min = min(a[i],b[i]); 25 p[i].position = i; 26 } 27 } 28 inline bool cmp(node x,node y){ 29 return x.Min < y.Min; 30 } 31 int main(){ 32 init(); 33 sort(p+1,p+1+n,cmp); 34 int tmph = 0,tmpt = n+1; 35 for(int i = 1;i <= n;i++) 36 if(p[i].Min == a[p[i].position]){tmph++;ans[tmph] = p[i].position;} 37 else{tmpt--;ans[tmpt] = p[i].position;} 38 int timea = 0,timeb = 0; 39 for(int i = 1;i <= n;i++){ 40 timea += a[ans[i]]; 41 if(timeb < timea)timeb = timea; 42 timeb += b[ans[i]]; 43 } 44 cout<<timeb<<endl; 45 for(int i = 1;i <= n;i++)printf("%d%c",ans[i],i == n ? ' ':' '); 46 return 0; 47 }
1 /* 2 problem:yibentong10004 3 date:2019/4/30 4 author:Lonely.Devil 5 */ 6 7 #include<iostream> 8 #include<cstdio> 9 #include<cstring> 10 #include<algorithm> 11 using namespace std; 12 const int maxn = 5e2+5; 13 struct node{ 14 int x,y; 15 }a[maxn]; 16 int vis[5000010]; 17 int flag,s; 18 int cmp(node a,node b){ 19 return a.y > b.y; 20 } 21 int main(){ 22 int m,n; 23 cin>>m>>n; 24 for(int i = 1;i <= n;i++)scanf("%d",&a[i].x); 25 for(int i = 1;i <= n;i++)scanf("%d",&a[i].y); 26 sort(a+1,a+n+1,cmp); 27 for(int i = 1;i <= n;i++){ 28 flag = 1; 29 for(int j = a[i].x;j >= 1;j--) 30 if(vis[j] == 0){ 31 flag = 0; 32 vis[j] = 1; 33 break; 34 } 35 if(flag == 1){ 36 for(int k = n;k >= 1;k--) 37 if(vis[k] == 0){ 38 vis[k] = 1; 39 break; 40 } 41 s += a[i].y; 42 } 43 } 44 printf("%d ",m-s); 45 return 0; 46 }
1 /* 2 problem:yibentonglian10000 3 date:2019/5/5 4 author:Lonely.Devil 5 */ 6 7 8 #include<iostream> 9 #include<algorithm> 10 #include<cstdio> 11 using namespace std; 12 const int maxn = 1e3+5; 13 int a[maxn]; 14 int n,Max,Min; 15 int main(){ 16 cin>>n; 17 for(int i = 1;i <= n; i++) 18 scanf("%d",&a[i]); 19 int tmp; 20 cin>>tmp; 21 sort(a+1,a+1+n); 22 Min = a[n]; 23 for(int i = 1;i < n;i++) 24 Min = Min*a[n-i]+1; 25 for(int i = 1;i <= n;i++){ 26 a[i+1] = a[i]*a[i+1]+1; 27 for(int j = i+1;j < n;j++) 28 if(a[j] > a[j+1]) 29 swap(a[j],a[j+1]); 30 } 31 Max = a[n]; 32 cout<<Max-Min<<endl; 33 return 0; 34 }
1 /* 2 problem:yibentonglian10001 3 date:2019/5/5 4 author:Lonely.Devil 5 */ 6 7 #include<iostream> 8 #include<cstdio> 9 using namespace std; 10 int n,m,ans,now; 11 int main(){ 12 cin>>n>>m; 13 for(int i = 1,tmp;i <= n;i++){ 14 scanf("%d",&tmp); 15 now += tmp; 16 if(now < m && i == n){ 17 ans++; 18 break; 19 } 20 if(now > m){ 21 ans++; 22 now = tmp; 23 } 24 if(now == m){ 25 ans++; 26 now = 0; 27 } 28 } 29 cout<<ans<<endl; 30 return 0; 31 }
1 /* 2 problem:yibentonglian10002 3 date:2019/5/5 4 author:Lonely.Devil 5 */ 6 7 #include<iostream> 8 #include<cstdio> 9 #include<algorithm> 10 using namespace std; 11 const int maxn = 1e6+5; 12 struct node{ 13 int x,y; 14 }a[maxn]; 15 int n,now,ans; 16 inline bool cmp(node a,node b){ 17 return a.y < b.y; 18 } 19 int main(){ 20 cin>>n; 21 for(int i = 1;i <= n;i++)scanf("%d%d",&a[i].x,&a[i].y); 22 sort(a+1,a+1+n,cmp); 23 now = a[1].y; 24 ans = 1; 25 for(int i = 2;i <= n;i++){ 26 if(a[i].x >= now){ 27 ans++; 28 now = a[i].y; 29 } 30 } 31 cout<<ans<<endl; 32 return 0; 33 }
1 /* 2 problem:yibentonglian10003 3 date:2019/5/5 4 author:Lonely.Devil 5 */ 6 7 #include<iostream> 8 #include<cstdio> 9 #include<cstring> 10 #include<algorithm> 11 using namespace std; 12 const int maxn = 1e6+5; 13 struct node{ 14 int date,val; 15 }a[maxn]; 16 bool visit[maxn]; 17 bool flag; 18 int n,ans,s; 19 inline bool cmp(node a,node b){ 20 return a.val > b.val; 21 } 22 int main(){ 23 cin>>n; 24 for(int i = 1;i <= n;i++)scanf("%d%d",&a[i].date,&a[i].val); 25 memset(visit,false,sizeof(visit)); 26 sort(a+1,a+1+n,cmp); 27 for(int i = 1;i <= n;i++){ 28 if(a[i].date <= s)continue; 29 flag = false; 30 for(int j = a[i].date;j >= 1;j--) 31 if(visit[j] == false){ 32 visit[j] = true; 33 ans += a[i].val; 34 flag = true; 35 break; 36 } 37 if(flag == false)s = a[i].date; 38 } 39 cout<<ans<<endl; 40 return 0; 41 }
1 /* 2 problem:yibentonglian10004 3 date:2019/5/5 4 author:Lonely.Devil 5 */ 6 7 #include<iostream> 8 #include<cstdio> 9 #include<cmath> 10 using namespace std; 11 const int maxn = 1e2+5; 12 int a[maxn],d[maxn],t[maxn],fish[maxn]; 13 int n,ans,h,sum,Max,position; 14 int main(){ 15 cin>>n>>h; 16 h *= 12; 17 for(int i = 1;i <= n;i++)scanf("%d",&a[i]); 18 for(int i = 1;i <= n;i++)scanf("%d",&d[i]); 19 for(int i = 1,tmp;i < n;i++)scanf("%d",&tmp),t[i] = t[i-1]+tmp; 20 for(int i = 1;i <= n;i++){ 21 for(int j = 1;j <= i;j++)fish[j] = a[j]; 22 int time = h - t[i-1]; 23 sum = 0; 24 for(int j = 1;j <= time;j++){ 25 Max = 0; 26 for(int k = 1;k <= i;k++) 27 if(fish[k] > Max)Max = fish[k],position = k; 28 if(Max == 0)break; 29 fish[position] -= d[position]; 30 sum += Max; 31 } 32 ans = max(ans,sum); 33 } 34 cout<<ans<<endl; 35 return 0; 36 }
1 /* 2 problem:yibentonglian10005 3 date:2019/5/7 4 author:Lonely.Devil 5 */ 6 7 #include<iostream> 8 #include<cstdio> 9 #include<algorithm> 10 #include<cmath> 11 using namespace std; 12 const int maxn = 1e6+5; 13 long long a[maxn],c[maxn]; 14 long long total,ave,ans; 15 int n; 16 int main(){ 17 cin>>n; 18 for(int i = 1;i <= n;i++)scanf("%d",&a[i]),total += a[i]; 19 ave = total/n; 20 for(int i = 1;i <= n;i++)c[i] = c[i-1]+a[i]-ave; 21 sort(c+1,c+1+n); 22 int mid = (n+1)>>1; 23 for(int i = 1;i <= n;i++) 24 ans += abs(c[mid]-c[i]); 25 printf("%lld ",ans); 26 return 0; 27 }
1 /* 2 problem:yibentong10000 3 date:2019/5/7 4 author:Lonely.Devil 5 */ 6 7 #include<iostream> 8 #include<cstdio> 9 using namespace std; 10 const int maxn = 1e5+5; 11 int a[maxn]; 12 int n,m,l,r; 13 inline bool check(int x){ 14 int ans = 1,sum = 0; 15 for(int i = 1;i <= n;i++){ 16 sum += a[i]; 17 if(sum > x)ans++,sum = a[i]; 18 } 19 if(ans <= m)return true; 20 return false; 21 } 22 int main(){ 23 cin>>n>>m; 24 int Max = 0,sum = 0; 25 for(int i = 1;i <= n;i++)scanf("%d",&a[i]),Max = max(Max,a[i]),sum += a[i]; 26 l = Max,r = sum; 27 while(l <= r){ 28 int mid = (l+r)>>1; 29 if(check(mid))r = mid-1; 30 else l = mid+1; 31 } 32 cout<<l<<endl; 33 return 0; 34 }
1 /* 2 problem:yibentong10001 3 date:2019/5/7 4 author:Lonely.Devil 5 */ 6 7 #include<iostream> 8 #include<cstdio> 9 #include<algorithm> 10 using namespace std; 11 const int maxn = 1e5+5; 12 int a[maxn]; 13 int n,m; 14 inline bool check(int x){ 15 int ans = 1; 16 int cnt = a[1]+x; 17 for(int i = 2;i <= n;i++){ 18 if(a[i] < cnt)continue; 19 ans++; 20 cnt = a[i]+x; 21 } 22 return ans >= m; 23 } 24 int main(){ 25 cin>>n>>m; 26 for(int i = 1;i <= n;i++)scanf("%d",&a[i]); 27 sort(a+1,a+1+n); 28 int l = 0,r = a[n]; 29 while(l <= r){ 30 int mid = (l+r)>>1; 31 if(check(mid))l = mid+1; 32 else r = mid-1; 33 } 34 cout<<r<<endl; 35 return 0; 36 }
法一：Kruscal
1 /* 2 problem:yibentong10002 3 date:2019/5/11 4 author:Lonely.Devil 5 */ 6 7 #include<iostream> 8 #include<cstdio> 9 #include<algorithm> 10 using namespace std; 11 #define ll long long 12 const ll maxn = 5e1+5; 13 ll father[maxn],x[maxn],y[maxn]; 14 ll n,cnt,sum; 15 struct edge{ 16 ll x,y,w; 17 }e[maxn*maxn/2]; 18 ll dist(ll i,ll j){ 19 return (abs(x[i]-x[j])+abs(y[i]-y[j])+1)/2; 20 } 21 ll cmp(edge a,edge b){ 22 return a.w < b.w; 23 } 24 ll find(ll x){ 25 if(father[x] == x)return x; 26 else return father[x] = find(father[x]); 27 } 28 void Kruscal(){ 29 sort(e+1,e+1+cnt,cmp); 30 for(ll i = 1;i <= cnt;i++) 31 if(find(e[i].x) != find(e[i].y)){ 32 father[find(e[i].x)] = find(e[i].y); 33 sum++; 34 if(sum == n-1){ 35 printf("%lld ",e[i].w); 36 break; 37 } 38 } 39 } 40 int main(){ 41 cin>>n; 42 for(ll i = 1;i <= n;i++)scanf("%d%d",&x[i],&y[i]); 43 for(ll i = 1;i <= n;i++)father[i] = i; 44 for(ll i = 1;i <= n;i++) 45 for(ll j = i+1;j <= n;j++){ 46 cnt++; 47 e[cnt].x = i; 48 e[cnt].y = j; 49 e[cnt].w = dist(i,j); 50 } 51 Kruscal(); 52 return 0; 53 }
法二：Floyd
1 /* 2 problem:yibentong1000 3 date:2019/5/11 4 author:Lonely.Devil 5 */ 6 7 #include<iostream> 8 #include<cstdio> 9 #include<algorithm> 10 using namespace std; 11 #define ll long long 12 const ll maxn = 5e1+5; 13 struct point{ 14 ll x,y; 15 }p[maxn]; 16 ll map[maxn][maxn]; 17 ll n,ans; 18 inline ll Abs(ll x){ 19 if(x < 0)x = -x; 20 return x; 21 } 22 inline ll Min(ll x,ll y){ 23 return x < y ? x : y; 24 } 25 inline ll Max(ll x,ll y){ 26 return x > y ? x : y; 27 } 28 inline ll dist(int i,int j){ 29 return (Abs(p[i].x-p[j].x)+Abs(p[i].y-p[j].y)+1)/2; 30 } 31 inline void Floyd(){ 32 for(ll k = 1;k <= n;k++) 33 for(ll i = 1;i <= n;i++) 34 for(ll j = 1;j <= n;j++) 35 map[i][j] = min(map[i][j],max(map[k][j],map[i][k])); 36 } 37 int main(){ 38 cin>>n; 39 for(ll i = 1;i <= n;i++)scanf("%lld%lld",&p[i].x,&p[i].y); 40 for(ll i = 1;i <= n;i++) 41 for(ll j = 1;j <= n;j++) 42 if(i == j)map[i][j] = 0; 43 for(ll i = 1;i <= n;i++) 44 for(ll j = i+1;j <= n;j++) 45 map[i][j] = map[j][i] = dist(i,j); 46 Floyd(); 47 for(ll i = 1;i <= n;i++) 48 for(ll j = i+1;j <= n;j++) 49 if(ans < map[i][j]) 50 ans = map[i][j]; 51 cout<<ans<<endl; 52 return 0; 53 }