Assign the task
Time Limit: 1 Sec Memory Limit: 256 MB
题目连接
http://acm.hdu.edu.cn/showproblem.php?pid=3974
Description
The company usually assigns
some tasks to some employees to finish.When a task is assigned to
someone,He/She will assigned it to all his/her subordinates.In other
words,the person and all his/her subordinates received a task in the
same time. Furthermore,whenever a employee received a task,he/she will
stop the current task(if he/she has) and start the new one.
Write
a program that will help in figuring out some employee’s current task
after the company assign some tasks to some employee.
Input
The first line contains a single positive integer T( T <= 10 ), indicates the number of test cases.
For each test case:
The first line contains an integer N (N ≤ 50,000) , which is the number of the employees.
The
following N - 1 lines each contain two integers u and v, which means
the employee v is the immediate boss of employee u(1<=u,v<=N).
The next line contains an integer M (M ≤ 50,000).
The following M lines each contain a message which is either
"C x" which means an inquiry for the current task of employee x
or
"T x y"which means the company assign task y to employee x.
(1<=x<=N,0<=y<=10^9)
Output
For each test case, print the test case number (beginning with 1) in the first line and then for every inquiry, output the correspond answer per line.
Sample Input
1
5
4 3
3 2
1 3
5 2
5
C 3
T 2 1
C 3
T 3 2
C 3
Sample Output
HINT
题意
给你一个森林,有两个操作
1.让某一个点,和他的儿子们全部染成X
2.查询某一个点是什么权值
题解:
当成单纯的图论跑一发就好,对于每一个查询直接跑到根位置就好,更新的时候,注意更新的时间问题
线段树也可以做,把一颗树的,全部放在一起,然后就区间更新就好,对于每一个点,记录他的位置,和他儿子最远能到哪儿。
代码:
//qscqesze
#include <cstdio>
#include <cmath>
#include <cstring>
#include <ctime>
#include <iostream>
#include <algorithm>
#include <set>
#include <vector>
#include <sstream>
#include <queue>
#include <typeinfo>
#include <fstream>
#include <map>
#include <stack>
typedef long long ll;
using namespace std;
//freopen("D.in","r",stdin);
//freopen("D.out","w",stdout);
#define sspeed ios_base::sync_with_stdio(0);cin.tie(0)
#define maxn 200001
#define mod 10007
#define eps 1e-9
int Num;
char CH[];
//const int inf=0x7fffffff; //нчоч╢С
const int inf=0x3f3f3f3f;
/* inline void P(int x)
{
Num=0;if(!x){putchar('0');puts("");return;}
while(x>0)CH[++Num]=x%10,x/=10;
while(Num)putchar(CH[Num--]+48);
puts("");
}
*/
//**************************************************************************************
inline ll read()
{
int x=,f=;char ch=getchar();
while(ch<''||ch>''){if(ch=='-')f=-;ch=getchar();}
while(ch>=''&&ch<=''){x=x*+ch-'';ch=getchar();}
return x*f;
}
inline void P(int x)
{
Num=;if(!x){putchar('');puts("");return;}
while(x>)CH[++Num]=x%,x/=;
while(Num)putchar(CH[Num--]+);
puts("");
}
struct node
{
int x,y;
}a[maxn];
int pa[maxn];
int main()
{
char s[];
int b,c;
int t=read();
for(int cas=;cas<=t;cas++)
{
int n=read();
memset(a,,sizeof(a));
memset(pa,-,sizeof(pa));
for(int i=;i<n-;i++)
{
int u=read(),v=read();
pa[u]=v;
}
for(int i=;i<=n;i++)
{
a[i].x=-;
a[i].y=-;
}
int m=read();
printf("Case #%d:\n",cas);
int co=;
for(int i=;i<m;i++)
{
scanf("%s",s);
if(s[]=='C')
{
b=read();
int k=a[b].x;
int y=a[b].y;
while(b!=-)
{
if(a[b].y>y)
{
k=a[b].x;
y=a[b].y;
}
b=pa[b];
}
printf("%d\n",k);
}
else
{
b=read(),c=read();
a[b].x=c;
a[b].y=++co;
}
}
}
}