最短路径

#include <bits/stdc++.h>
using namespace std;
#define MAX 200
#define INF 0x7fffffff
//下标从1开始
int graph[MAX + 1][MAX + 1], points[MAX + 1], m, n;
//任意图，只要权值是正即可
//动态规划算法，取最小值时可以用堆（优先队列）
//只能运算符重载 < 。。。。,好像是因为接口的原因。
struct data
{
    int n, d;
    data(int n, int d)
    {
        this->d = d;
        this->n = n;
    }
    //注意 后面的const必须写
    bool operator< (data const &a) const
    {
        return this->d>a.d;
    }
};
void show_dj(int path[],int n,int source){
    if(source==n){
        cout<<n<<"->";
    }else{
        show_dj(path,path[n],source);
        cout<<n<<"->";
    }
}
void dijkstra(int source)
{
    //path 存前驱路径
    int path[MAX + 1], ok[MAX + 1],d[MAX+1];//d是距离，只存不找
    priority_queue<data,vector<data> > pq;
    memset(ok, 0, sizeof(ok));
    ok[source]=1;
    for (int i = 1; i <= n; i++)
    {
        if(graph[source][i]<INF){
            path[i] = source;
            d[i]=graph[source][i];
            pq.push(data(i,graph[source][i]));
        }else {
            path[i] = i;
            d[i]=INF;
        } 
    }
//如果需要改动队列的内容，所以直接插入新的data，因为新的一定比旧的小，
//所以肯定现出来，但是必须用ok判断一下
    while(!pq.empty()){
        data p=pq.top();
        pq.pop();
        if(ok[p.n]==1) continue;
        ok[p.n]=1;
        show_dj(path,p.n,source);
        cout<<endl;
        for(int i=1;i<=n;i++){
            if(!ok[i]&&graph[p.n][i]<INF){
                if(p.d+graph[p.n][i]<d[i]){
                    d[i]=p.d+graph[p.n][i];
                    path[i]=p.n;
                    pq.push(data(i,d[i]));
                }
            }
        }
    }
}

int main()
{
    cin >> n >> m;
    for (int i = 1; i <= n; i++)
        for (int j = 1; j <= n; j++)
            graph[i][j] = INF;
    for (int i = 1; i <= n; i++)
        points[i] = i;
    for (int i = 0; i < m; i++)
    {
        int x, y, z;
        cin >> x >> y >> z;
        graph[x][y] = z;
    }
    for (int i = 1; i <= n; i++)
    {
        for (int j = 1; j <= n; j++)
            cout << graph[i][j] << " ";
        cout << endl;
    }
    dijkstra(1);
    return 0;
}