python/TangDou/LuoGuBook/L18_2_2_2.cpp

#include <bits/stdc++.h>

using namespace std;

const int N = 1005; //图的最大点数量
struct edge {       //记录边的终点，边权的结构体
    int to;         //终点
    int cost;       //边权
};
int n, m; //表示图中有n个点，m条边
vector<edge> p[N];  //使用vector的邻接表

int v[N][N]; //邻接矩阵

/**
 * 测试数据
 4 6
 2 1 1
 1 3 2
 4 1 4
 2 4 6
 4 2 3
 3 4 5
 */
int main() {
    cin >> n >> m;
    //m条边
    for (int i = 1; i <= m; i++) {
        int u, v, l;                //点u到点v有一条权值为l的边
        cin >> u >> v >> l;
        p[u].push_back({v, l});
    }

    //读入到邻接矩阵
    for (int i = 1; i <= n; i++)
        for (int j = 0; j < p[i].size(); j++)
            v[i][p[i][j].to] = p[i][j].cost;

    //按邻接矩阵输出
    for (int i = 1; i <= n; i++) {
        for (int j = 1; j <= n; j++)
            cout << v[i][j] << " ";
        cout << endl;
    }
    return 0;
}