- 模板题
bzoj1036
1 #include<stdio.h> 2 #include<algorithm> 3 using namespace std; 4 5 #define lson rt<<1,l,mid 6 #define rson rt<<1|1,mid+1,r 7 #define maxn 30005 8 #define inf 0x3f3f3f3f 9 struct node{ 10 int sum,max; 11 }tree[maxn<<2]; 12 int cnt,v[maxn<<1],w[maxn<<1],next[maxn<<1],first[maxn]; 13 int nn,size[maxn],son[maxn],dep[maxn],fa[maxn],top[maxn],Map[maxn]; 14 15 void add(int st,int end){ 16 v[++cnt]=end; 17 next[cnt]=first[st]; 18 first[st]=cnt; 19 } 20 void dfs(int sss){ 21 size[sss]=1; 22 son[sss]=0; 23 for(int e=first[sss];e;e=next[e]){ 24 if(v[e]!=fa[sss]){ 25 fa[v[e]]=sss; 26 dep[v[e]]=dep[sss]+1; 27 dfs(v[e]); 28 if(size[v[e]]>size[son[sss]])son[sss]=v[e]; 29 size[sss]+=size[v[e]]; 30 } 31 } 32 } 33 void build(int sss,int anc){ 34 Map[sss]=++nn;top[sss]=anc; 35 if(son[sss])build(son[sss],anc); 36 for(int e=first[sss];e;e=next[e]) 37 if(v[e]!=fa[sss]&&v[e]!=son[sss]) 38 build(v[e],v[e]); 39 } 40 void update(int rt,int l,int r,int pos,int x){ 41 if(l==r){ 42 tree[rt].max=tree[rt].sum=x; 43 return; 44 } 45 int mid=(l+r)>>1; 46 if(pos<=mid)update(lson,pos,x); 47 else update(rson,pos,x); 48 tree[rt].max=max(tree[rt<<1].max,tree[rt<<1|1].max); 49 tree[rt].sum=tree[rt<<1].sum+tree[rt<<1|1].sum; 50 } 51 int sec_max(int rt,int l,int r,int ql,int qr){ 52 if(ql<=l&&qr>=r)return tree[rt].max; 53 int ans=-inf,mid=(l+r)>>1; 54 if(ql<=mid)ans=max(ans,sec_max(lson,ql,qr)); 55 if(qr>mid)ans=max(ans,sec_max(rson,ql,qr)); 56 return ans; 57 } 58 int max_op(int va,int vb){ 59 int ans=-inf,f1=top[va],f2=top[vb]; 60 while(f1!=f2){ 61 if(dep[f1]<dep[f2])swap(f1,f2),swap(va,vb); 62 ans=max(ans,sec_max(1,1,nn,Map[f1],Map[va])); 63 va=fa[f1];f1=top[va]; 64 } 65 if(dep[va]>dep[vb])swap(va,vb); 66 return max(ans,sec_max(1,1,nn,Map[va],Map[vb])); 67 } 68 int query(int rt,int l,int r,int ql,int qr){ 69 if(ql<=l&&qr>=r)return tree[rt].sum; 70 int ans=0,mid=(l+r)>>1; 71 if(ql<=mid)ans+=query(lson,ql,qr); 72 if(qr>mid)ans+=query(rson,ql,qr); 73 return ans; 74 } 75 int sum_op(int va,int vb){ 76 int ans=0,f1=top[va],f2=top[vb]; 77 while(f1!=f2){ 78 if(dep[f1]<dep[f2])swap(f1,f2),swap(va,vb); 79 ans+=query(1,1,nn,Map[f1],Map[va]); 80 va=fa[f1];f1=top[va]; 81 } 82 if(dep[va]>dep[vb])swap(va,vb); 83 return ans+query(1,1,nn,Map[va],Map[vb]); 84 } 85 int main(){ 86 int n,x,q,a,b; 87 scanf("%d",&n); 88 for(int i=1;i<n;i++){ 89 scanf("%d%d",&a,&b); 90 add(a,b);add(b,a); 91 } 92 dfs(1); 93 build(1,1); 94 for(int i=1;i<=n;i++){ 95 scanf("%d",&x); 96 update(1,1,nn,Map[i],x); 97 } 98 scanf("%d",&q); 99 for(int i=1;i<=q;i++){ 100 char op[15]; 101 scanf("%s%d%d",op,&a,&b); 102 if(op[0]=='C')update(1,1,nn,Map[a],b); 103 else{ 104 if(op[1]=='M')printf("%d ",max_op(a,b)); 105 else printf("%d ",sum_op(a,b)); 106 } 107 } 108 return 0; 109 }
- 坑B题
bzoj2243
1 #include<stdio.h> 2 #include<algorithm> 3 using namespace std; 4 5 #define maxn 100005 6 #define lson rt<<1,l,mid 7 #define rson rt<<1|1,mid+1,r 8 struct node{ 9 int sum,lc,rc,mark; 10 }tree[maxn<<2]; 11 int cnt,v[maxn<<1],next[maxn<<1],first[maxn]; 12 int nn,lcol,rcol,col[maxn],size[maxn],son[maxn],dep[maxn],fa[maxn],bel[maxn],Map[maxn],top[maxn]; 13 14 void add(int st,int end){ 15 v[++cnt]=end; 16 next[cnt]=first[st]; 17 first[st]=cnt; 18 } 19 20 void dfs(int sss){ 21 size[sss]=1; 22 son[sss]=0; 23 for(int e=first[sss];e;e=next[e]){ 24 if(v[e]!=fa[sss]){ 25 fa[v[e]]=sss; 26 dep[v[e]]=dep[sss]+1; 27 dfs(v[e]); 28 if(size[v[e]]>size[son[sss]])son[sss]=v[e]; 29 size[sss]+=size[v[e]]; 30 } 31 } 32 } 33 34 void hash(int sss,int anc){ 35 Map[sss]=++nn;bel[nn]=sss;top[sss]=anc; 36 if(son[sss])hash(son[sss],anc); 37 for(int e=first[sss];e;e=next[e]) 38 if(v[e]!=fa[sss]&&v[e]!=son[sss])hash(v[e],v[e]); 39 } 40 41 void push_up(int rt){ 42 tree[rt].lc=tree[rt<<1].lc; 43 tree[rt].rc=tree[rt<<1|1].rc; 44 tree[rt].sum=tree[rt<<1].sum+tree[rt<<1|1].sum-(tree[rt<<1].rc==tree[rt<<1|1].lc); 45 } 46 47 void push_down(int rt){ 48 if(tree[rt].mark!=-1){ 49 tree[rt<<1].lc=tree[rt<<1].rc=tree[rt<<1].mark=tree[rt].mark; 50 tree[rt<<1|1].lc=tree[rt<<1|1].rc=tree[rt<<1|1].mark=tree[rt].mark; 51 tree[rt<<1].sum=tree[rt<<1|1].sum=1; 52 tree[rt].mark=-1; 53 } 54 } 55 56 void build(int rt,int l,int r){ 57 tree[rt].mark=-1; 58 if(l==r){ 59 tree[rt].lc=tree[rt].rc=col[bel[l]]; 60 tree[rt].sum=1; 61 return; 62 } 63 int mid=(l+r)>>1; 64 build(lson);build(rson); 65 push_up(rt); 66 } 67 68 int query(int rt,int l,int r,int ql,int qr){ 69 if(l==ql)lcol=tree[rt].lc; 70 if(r==qr)rcol=tree[rt].rc; 71 if(ql<=l&&qr>=r)return tree[rt].sum; 72 push_down(rt); 73 int ans=0,t1=-1,t2=-1,mid=(l+r)>>1; 74 if(ql<=mid)ans+=query(lson,ql,qr),t1=tree[rt<<1].rc; 75 if(qr>mid)ans+=query(rson,ql,qr),t2=tree[rt<<1|1].lc; 76 ans-=(t1==t2&&t1!=-1); 77 return ans; 78 } 79 80 int query_op(int va,int vb){ 81 int ans=0,t1=-1,t2=-1,f1=top[va],f2=top[vb]; 82 while(f1!=f2){ 83 if(dep[f1]<dep[f2])swap(f1,f2),swap(va,vb),swap(t1,t2); 84 ans+=(query(1,1,nn,Map[f1],Map[va])-(t1==rcol)); 85 t1=lcol; 86 va=fa[f1];f1=top[va]; 87 } 88 if(dep[va]<dep[vb])swap(va,vb),swap(t1,t2);//important 89 ans+=(query(1,1,nn,Map[vb],Map[va])-(t1==rcol&&t1!=-1)-(t2==lcol&&t2!=-1)); 90 return ans; 91 } 92 93 void update(int rt,int l,int r,int ql,int qr,int c){ 94 if(ql<=l&&qr>=r){ 95 tree[rt].lc=tree[rt].rc=tree[rt].mark=c; 96 tree[rt].sum=1; 97 return; 98 } 99 push_down(rt); 100 int mid=(l+r)>>1; 101 if(ql<=mid)update(lson,ql,qr,c); 102 if(qr>mid)update(rson,ql,qr,c); 103 push_up(rt); 104 } 105 106 void update_op(int va,int vb,int c){ 107 int f1=top[va],f2=top[vb]; 108 while(f1!=f2){ 109 if(dep[f1]<dep[f2])swap(f1,f2),swap(va,vb); 110 update(1,1,nn,Map[f1],Map[va],c); 111 va=fa[f1];f1=top[va]; 112 } 113 if(dep[va]>dep[vb])swap(va,vb); 114 update(1,1,nn,Map[va],Map[vb],c); 115 } 116 117 int main(){ 118 freopen("1.in","r",stdin); 119 int n,m,a,b,c; 120 scanf("%d%d",&n,&m); 121 for(int i=1;i<=n;i++) 122 scanf("%d",&col[i]); 123 for(int i=1;i<n;i++){ 124 scanf("%d%d",&a,&b); 125 add(a,b);add(b,a); 126 } 127 dfs(1); 128 hash(1,1); 129 build(1,1,nn); 130 for(int i=1;i<=m;i++){ 131 char op[5]; 132 scanf("%s%d%d",op,&a,&b); 133 if(op[0]=='Q') printf("%d ",query_op(a,b)); 134 else { 135 scanf("%d",&c); 136 update_op(a,b,c); 137 } 138 } 139 return 0; 140 }
永远的痛，注释里的important，老夫没有注意到这道题的特殊性质，于是这一行还是按上道题内种方式写的，于是BOOM
由于是在恶补知识点之前学的，所以并没有老爷题yoooo～