ZOJ Problem Set - 3708 Density of Power Network

http://acm.zju.edu.cn/onlinejudge/showProblem.do?problemCode=3708

 

#include 
#include 
int main(int argc, char *argv[])
{
	int T,i,j,lineSum;
	int N,M;	 
	int x[505],y[505]; 
	int lineL [505][505] ;
	
	scanf("%d",&T); 
	for(i = 0 ; i < T ;i++){                    
		lineSum = 0;       		
		scanf("%d %d",&N,&M); 
		
		
		memset (lineL,0,sizeof(lineL));	
		memset (lineL,0,sizeof(x));
		memset (lineL,0,sizeof(y));
		
		for(j = 0 ; j < M ;j++){	
			scanf("%d",&x[j]); 		
		} 
		for(j = 0 ; j < M ;j++){
			scanf("%d",&y[j]); 
		}
		for(j = 0 ; j < M ;j++){
			if(lineL[x[j]][y[j]] == 0 && lineL[y[j]][x[j]] == 0){
				
				lineSum ++;
				lineL[x[j]][y[j]]=lineL[y[j]][x[j]]=1;	
				
			}
		}		
		printf("%.3f\n",lineSum/(N*1.0)); 
	} 
	
	return 0;
}