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Labeling Balls 3687(拓扑排序+反向建图)


Labeling Balls


Time Limit: 1000MS

 

Memory Limit: 65536K

Total Submissions: 12262

 

Accepted: 3511


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:

  1. No two balls share the same label.
  2. The labeling satisfies several constrains like "The ball labeled with a is lighter than the one labeled with b".

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, bN) 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

#include<cstdio>
#include<cstdlib>
#include<cstring>
using namespace std;
int map[210][210];
int queue[210];
int indegree[210];
int n,m;
void INPUT(){
	int i,a,b;
	memset(map,0,sizeof(map));
	memset(indegree,0,sizeof(indegree));
	scanf("%d%d",&n,&m);
	for(i=0;i<m;++i)
	{
		scanf("%d%d",&a,&b);
		if(map[b][a]==0)
		{
			map[b][a]=1;
			indegree[a]++;
		}
	}
}
void Topo(){
	int i,j,top,num=0;
	for(j=n;j>=1;--j)
	{
		top=-1;
		for(i=n;i>=1;--i)
		{
			if(indegree[i]==0)
			{
				top=i;break;
			}
		}
		if(top==-1)break;
		queue[top]=j;indegree[top]=-1;
		for(i=1;i<=n;++i)
		{
			if(map[top][i])
			{
				indegree[i]--;
			}
		}
	}
	if(j!=0){
		printf("-1\n");
	}
	else{
		for(i=1;i<=n;++i)
		{
			printf(i==1?"%d":" %d",queue[i]);
		}
		printf("\n");
	}
}
int main()
{
	int t;
	scanf("%d",&t);
	while(t--){
		INPUT();
		Topo();
	}
	return 0;
}


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