Hdu 2544 最短路

图论入门题。第一次写的时候用的是比较麻烦的模板，第二次写的时候模板精简多啦。还得要多多努力~

较麻烦的模板，CODE： 

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
using namespace std;


const int INF = 0x0fffffff;
const int SIZE = 110;
int graph[SIZE][SIZE];
int vis[SIZE], dis[SIZE];
int n, m;


void Dijkstra(int src)
{
    int i, j;
    int min, v;
    for(i = 1; i <= n; i++) dis[i] = graph[src][i];
    dis[src] = 0;
    vis[src] = 1;
    for(i = 1; i < n; i++)
    {
        min = INF;
        for(j = 1; j <= n; j++)
        {
            if(!vis[j] && dis[j] < min)
            {
                min = dis[j];
                v = j;
            }
        }
        vis[v] = 1;
        for(j = 1; j <= n; j++)
        {
            if(!vis[j] && (dis[j] > min+graph[v][j]))
            {
                dis[j] = min + graph[v][j];
            } //类似Prim, dis[j] <?= graph[v][j];
        }
    }
    return ;
}




void init()
{
    memset(vis, 0, sizeof(vis));
    memset(dis, 0, sizeof(dis));
    memset(graph, 0, sizeof(graph));
    for(int i = 1; i <= n; i++)
    {
        for(int j = 1; j <= n; j++)
        {
            graph[i][j] = graph[j][i] = INF;
        }
    }
    return ;
}


int main()
{
    int u, v, w1;
    while(~scanf("%d%d", &n, &m))
    {
        if(n == 0 && m == 0) break;
        init();
        for(int i = 0 ; i < m; i++)
        {
            scanf("%d%d%d", &u, &v, &w1);
            graph[u][v] = graph[v][u] = w1;
        }
        Dijkstra(1);
        printf("%d\n", dis[n]);
    }

} 

 

精简的模板，CODE：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
using namespace std;


const int INF = 0x0fffffff;
const int SIZE = 101;
int w[SIZE][SIZE];
int d[SIZE], v[SIZE];
int N, M;

void Dijkstra(int src)
{
    int i, j;
    for(i = 1; i <= N; i++) d[i] = (i == src ? 0 : INF);
    for(i = 1; i < N; i++)
    {
        int x, m = INF;
        for(int y = 1; y <= N; y++) if(!v[y] && d[y] <= m) m = d[x=y];  //min
        v[x] = 1;
        for(int y = 1; y <= N; y++) d[y] <?= d[x] + w[x][y];   //松弛 
    }       //类似Prim, d[y] <?= w[x][y];
    return ;
} //Dijkstra


void init()
{
    memset(w, 0, sizeof(w));
    memset(d, 0, sizeof(d));
    memset(v, 0, sizeof(v));
    for(int i = 1; i <= N; i++)
    {
        for(int j = 1; j <= N; j++)
        {
            w[i][j] = INF;
        }
    }
    return ;
}

int main()
{
    while(~scanf("%d", &N), N)
    {
        init();
        for(scanf("%d", &M); M > 0; M--)
        {
            int u, v, w1;
            scanf("%d%d%d", &u, &v, &w1);
            w[u][v] = w[v][u] = w1;
        }
        Dijkstra(1);
        printf("%d\n", d[N]);
    }

}