最短路水题 HDU 1874畅通工程续

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3 3
0 1 1
0 2 3
1 2 1
0 2
3 1
0 1 1
1 2 

2
-1 

#include<stdio.h>
#include<string.h>
#define MAX 2000001
int dist[1005];
int c[205][205];
int n,m;
bool s[205];
int cnt = 0;
void Dijkstra(int v)
{
	int u;
	dist[v] = 0;
	for(int j = 0;j < n;j ++)
	{
		u = -1;
		int tmp = MAX;
		//找到dist中最小的值得下标 
		for(int i = 0;i < n;i ++)
			if(s[i]&&dist[i] < tmp)
			{
				tmp = dist[i];
				u=i;	
			}
		if(u == -1)
			break;
		s[u] = false;
		//更新dist 
		for(int i = 0;i < n;i ++)
		{
			int sum = c[u][i] + dist[u];
			if(s[i]&&dist[i] > sum)
			{
				dist[i] = sum;
			}
		}
	}
	
}
int main()
{
	//freopen("out.txt","r",stdin);
	//freopen("in.txt","w",stdout);
	while(~scanf("%d%d",&n,&m))
	{
		for(int i = 0;i < n;i ++)
			for(int j = 0;j < n;j ++)
				c[i][j] = MAX;
		for(int i = 0;i < n;i ++)
		{
			dist[i] = MAX;
			s[i] = true;
		}
			
		for(int i = 0;i < m;i ++)
		{
			int a,b,x;
			scanf("%d%d%d",&a,&b,&x);
			if(c[a][b]>x)
			{
				c[a][b]=x;
				c[b][a]=x;	
			}
		}
		int x,y;
		scanf("%d %d",&x,&y);
		Dijkstra(x);
		if(dist[y] >= MAX)
		dist[y] = -1;
		printf("%d\n",dist[y],cnt ++);
	}
	return 0;
}

最短路水题 HDU 1874畅通工程续

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原文地址：http://blog.csdn.net/advanced_hwr/article/details/51347441