suoi14 子树查找 (dfs)
把询问记下来，然后开个桶差分
1 #include<bits/stdc++.h> 2 #define pa pair<int,int> 3 #define lowb(x) ((x)&(-(x))) 4 #define REP(i,n0,n) for(i=n0;i<=n;i++) 5 #define PER(i,n0,n) for(i=n;i>=n0;i--) 6 #define MAX(a,b) ((a>b)?a:b) 7 #define MIN(a,b) ((a<b)?a:b) 8 #define CLR(a,x) memset(a,x,sizeof(a)) 9 #define rei register int 10 using namespace std; 11 typedef long long ll; 12 const int maxn=1e6+10; 13 14 inline ll rd(){ 15 ll x=0;char c=getchar();int neg=1; 16 while(c<'0'||c>'9'){if(c=='-') neg=-1;c=getchar();} 17 while(c>='0'&&c<='9') x=x*10+c-'0',c=getchar(); 18 return x*neg; 19 } 20 21 int N,v[maxn],q[maxn]; 22 int ch[maxn],hd[maxn]; 23 int cnt[maxn],ans[maxn]; 24 25 void dfs(int x,int f){ 26 int cc=cnt[q[x]];cnt[v[x]]++; 27 for(int i=hd[x];i;i=ch[i]){ 28 if(i==f) continue; 29 dfs(i,x); 30 }ans[x]=cnt[q[x]]-cc; 31 } 32 33 int main(){ 34 //freopen(".in","r",stdin); 35 rei i,j,k; 36 N=rd(); 37 for(i=1;i<=N;i++) v[i]=rd(),q[i]=rd(); 38 for(i=2;i<=N;i++){ 39 int a=rd(); 40 ch[i]=hd[a];hd[a]=i; 41 } 42 dfs(1,0); 43 for(i=1;i<=N;i++) printf("%d\n",ans[i]); 44 return 0; 45 }
