tjut 3974

来源：互联网发布：java工程师就业班编辑：程序博客网时间：2024/06/17 15:28
#include <stdio.h>#include <string.h>#include <iostream>#include <algorithm>#include <vector>#include <queue>#include <set>#include <map>#include <string>#include <math.h>#include <stdlib.h>#include <time.h>using namespace std;const int MAXN = 50010;struct Edge{    int to,next;}edge[MAXN];int head[MAXN],tot;int cnt;int start[MAXN],end1[MAXN];void init(){    cnt = 0;    tot = 0;    memset(head,-1,sizeof(head));}void addedge(int u,int v){    edge[tot].to = v;    edge[tot].next = head[u];    head[u] = tot++;}void dfs(int u){    ++cnt;    start[u] = cnt;    for(int i = head[u];i != -1;i = edge[i].next)    {        dfs(edge[i].to);    }    end1[u] = cnt;}struct Node{    int l,r;    int val;    int lazy;}segTree[MAXN*4];void Update_Same(int r,int v){    if(r)    {        segTree[r].val = v;        segTree[r].lazy = 1;    }}void push_down(int r){    if(segTree[r].lazy)    {        Update_Same(r<<1,segTree[r].val);        Update_Same((r<<1)|1,segTree[r].val);        segTree[r].lazy = 0;    }}void Build(int i,int l,int r){    segTree[i].l = l;    segTree[i].r = r;    segTree[i].val = -1;    segTree[i].lazy = 0;    if(l == r)return;    int mid = (l+r)/2;    Build(i<<1,l,mid);    Build((i<<1)|1,mid+1,r);}void update(int i,int l,int r,int v){    if(segTree[i].l == l && segTree[i].r == r)    {        Update_Same(i,v);        return;    }    push_down(i);    int mid = (segTree[i].l + segTree[i].r)/2;    if(r <= mid)update(i<<1,l,r,v);    else if(l > mid)update((i<<1)|1,l,r,v);    else    {        update(i<<1,l,mid,v);        update((i<<1)|1,mid+1,r,v);    }}int query(int i,int u){    if(segTree[i].l == u && segTree[i].r == u)        return segTree[i].val;    push_down(i);    int mid = (segTree[i].l + segTree[i].r)/2;    if(u <= mid)return query(i<<1,u);    else return query((i<<1)|1,u);}bool used[MAXN];int main(){    //freopen("in.txt","r",stdin);    //freopen("out.txt","w",stdout);    int n;    int T;    scanf("%d",&T);    int iCase = 0;    while(T--)    {        iCase++;        printf("Case #%d:\n",iCase);        int u,v;        memset(used,false,sizeof(used));        init();        scanf("%d",&n);        for(int i = 1;i < n;i++)        {            scanf("%d%d",&u,&v);            used[u] = true;            addedge(v,u);        }        for(int i = 1;i <= n;i++)            if(!used[i])            {                dfs(i);                break;            }        Build(1,1,cnt);        char op[10];        int m;        scanf("%d",&m);        while(m--)        {            scanf("%s",op);            if(op[0] == 'C')            {                scanf("%d",&u);                printf("%d\n",query(1,start[u]));            }            else            {                scanf("%d%d",&u,&v);                update(1,start[u],end1[u],v);            }        }    }    return 0;}
0 0