there can be double edges
> I think this problem solve by Dijkstra Algorithm. 
> and I don't think this algorithm get TL or WA , in N<=1000,T<=2000
> but.,,.,.,
> I got WA... It's very strange .. :(
> please help me .
> 
> My Code : 
> /***CodeStart***/
> #include <stdio.h>
> 
> int t, n ; 
> int a[ 1010 ][ 1010 ] ; 
> int v[ 1010 ] ; 
> int d[ 1010 ] ; 
> 
> void input();
> void process();
> void output();
>  
> int main()
> {
> 	input();
> 	process();
> 	output();
> 	return 0 ; 
> }
> void input()
> {
> 	scanf("%d %d",&t,&n);
> 	int i ,  j ;
> 	for ( i = 1 ; i <= n ; i ++ )
> 		for ( j = 1 ; j <= n; j ++ )
> 		{
> 			if ( i == j ) a[i][j] = 0 ;
> 			else a[i][j] = 2100000000 ; 
> 		}
> 	int t1, t2 , t3 ; 
> 	for ( i = 0 ; i < t ; i ++ )
> 	{
> 		scanf("%d %d %d",&t1,&t2,&t3 ) ;  
> 		a[t1][t2] = t3 ; 
> 		a[t2][t1] = t3 ; 
> 	}
> }
> void process()
> {
> 	int i , j ;
> 	int min , mini ; 
> 	for ( i = 1 ; i <= n ; i ++ ) 
> 	{
> 		d[i] = 2100000000 ; 
> 		v[i] = 0 ;
> 	}
> 	d[1]=0;
> 	for ( i = 1 ; i <= n ; i ++ ) 
> 	{
> 		min = 2100000000; 
> 		for ( j = 1 ; j <= n ; j ++ )
> 		{
> 			if ( v[j] == 0 && min > d[j] )
> 			{
> 				min = d[j] ;
> 				mini = j ;
> 			}
> 		}
> 		v[mini] = 1 ; 
> 		for ( j = 1 ; j <= n ; j ++ )
> 			if ( d[j] > d[mini] + a[mini][j] ) 
> 				d[j] = d[mini] + a[mini][j] ; 
> 	}
> }
> 
> void output()
> {
> 	printf("%d\n",d[n]);
> }
> /*** Code End ***/