[HDOJ3974]Assign the task（建树胡搞）

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=3974

出现在窝bin的线段树专题里…第一时间想的是记录入度找出根节点，然后标记深度转换到线段树中。但是发现并不会这个姿势…于是直接深搜更新了…发现没有退化成链的数据。于是水水地过去了………………

 #include <algorithm>
 #include <iostream>
 #include <iomanip>
 #include <cstring>
 #include <climits>
 #include <complex>
 #include <fstream>
 #include <cassert>
 #include <cstdio>
 #include <bitset>
 #include <vector>
 #include <deque>
 #include <queue>
 #include <stack>
 #include <ctime>
 #include <set>
 #include <map>
 #include <cmath>

 using namespace std;

 #define fr first
 #define sc second
 #define pb(a) push_back(a)
 #define Rint(a) scanf("%d", &a)
 #define Rll(a) scanf("%I64d", &a)
 #define Rs(a) scanf("%s", a)
 #define FRead() freopen("in", "r", stdin)
 #define FWrite() freopen("out", "w", stdout)
 #define Rep(i, len) for(int i = 0; i < (len); i++)
 #define For(i, a, len) for(int i = (a); i < (len); i++)
 #define Cls(a) memset((a), 0, sizeof(a))
 #define Clr(a, x) memset((a), (x), sizeof(a))
 #define Full(a) memset((a), 0x7f7f, sizeof(a))

 #define lrt rt << 1
 #define rrt rt << 1 | 1
 const int maxn = ;
 int n, m;
 int in[maxn];
 int depth[maxn];
 bool vis[maxn];
 vector<int> G[maxn];
 int q[maxn], front, tail;
 int task[maxn];

 void bfs(int rt) {
     front = tail = ;
     int lv = ;
     depth[rt] = lv++; q[tail++] = rt; vis[rt] = ;
     while(front < tail) {
         int u = q[front++];
         Rep(i, G[u].size()) {
             if(!vis[G[u][i]]) {
                 vis[G[u][i]] = ;
                 depth[G[u][i]] = lv;
                 q[tail++] = G[u][i];
             }
         }
         lv++;
     }
 }

 void update(int rt, int p) {
     task[rt] = p;
     Rep(i, G[rt].size()) {
         update(G[rt][i], p);
     }
 }

 int main() {
     // FRead();
     int T, _ = ;
     Rint(T);
     int u, v;
     char cmd[];
     while(T--) {
         Rint(n);
         Rep(i, n+) G[i].clear();
         Cls(depth); Cls(vis); Cls(in); Clr(task, -);
         Rep(i, n-) {
             Rint(u); Rint(v);
             G[v].push_back(u); in[u]++;
         }
         int rt = -;
         For(i, , n+) if(!in[i]) rt = i;
         bfs(rt);
         Rint(m);
         printf("Case #%d:\n", _++);
         while(m--) {
             Rs(cmd);
             if(cmd[] == 'C') {
                 Rint(u);
                 printf("%d\n", task[u]);
             }
             if(cmd[] == 'T') {
                 Rint(u); Rint(v);
                 update(u, v);
             }
         }
     }
     return ;
 }