标签：des style http color os strong
| Time Limit: 1000MS | Memory Limit: 65536K | |
| Total Submissions: 10220 | Accepted: 2838 |
Description
Windy has N balls of distinct weights from 1 unit to N units. Now he tries to label them with 1 to N in such a way that:
Can you help windy to find a solution?
Input
The first line of input is the number of test case. The first line of each test case contains two integers, N (1 ≤ N ≤ 200) and M (0 ≤ M ≤ 40,000). The next M line each contain two integers a and b indicating the ball labeled with a must be lighter than the one labeled with b. (1 ≤ a, b ≤ N) There is a blank line before each test case.
Output
For each test case output on a single line the balls‘ weights from label 1 to label N. If several solutions exist, you should output the one with the smallest weight for label 1, then with the smallest weight for label 2, then with the smallest weight for label 3 and so on... If no solution exists, output -1 instead.
Sample Input
5 4 0 4 1 1 1 4 2 1 2 2 1 4 1 2 1 4 1 3 2
Sample Output
1 2 3 4 -1 -1 2 1 3 4 1 3 2 4
Source
POJ Founder Monthly Contest – 2008.08.31, windy7926778
AC代码：
#include<iostream>
#include<queue>
#include<stack>
#include<vector>
#include<cstring>
#include<algorithm>
using namespace std;
int n,m;
int f1;
int r[205];
int ans_r[205];
int in[205];
vector <int> a[205];
void top_sort(){
int t=n;
priority_queue <int> s;
while(!s.empty())
s.pop();
f1=0;
for(int i=1;i<=n;i++)
if(in[i]==0)
s.push(i);
while(!s.empty()){
int tmp=s.top();
s.pop();
r[tmp]=t--; //优先给大编号分配最重的球
for(int i=0;i<a[tmp].size();i++){
in[a[tmp][i]]--;
if(in[a[tmp][i]]==0)
s.push(a[tmp][i]);
}
}
if(t>0)
f1=1;
}
int main(){
int T; cin>>T;
while(T--){
memset(in,0,sizeof(in));
for(int i=0;i<=n;i++)
if(!a[i].empty()){
a[i].clear();
}
cin>>n>>m;
for(int i=0;i<m;i++){
int j,x,y;
cin>>x>>y;
for(j=0;j<a[y].size();j++)
if(a[y][j]==x)
break;
if(j>=a[y].size()){
a[y].push_back(x); //重的编号指向轻的编号
in[x]++; //轻的编号的入度加1，为了在top_sort的时候优先给重的编号分配重量
}
}
top_sort();
if(f1==1)
cout<<"-1"<<endl;
else {
for(int i=1;i<=n;i++)
cout<<r[i]<<' ';
cout<<endl;
}
}
return 0;
}
标签：des style http color os strong
原文地址：http://blog.csdn.net/my_acm/article/details/38052177
