C - Heavy Transportation POJ - 1797

#include <iostream>
#include <vector>
#include <algorithm>
#include <string>
#include <set>
#include <queue>
#include <map>
#include <sstream>
#include <cstdio>
#include <cstring>
#include <numeric>
#include <cmath>
#include <iomanip>
#include <deque>
#include <bitset>
//#include <unordered_set>
//#include <unordered_map>
//#include <bits/stdc++.h>
//#include <xfunctional>
#define ll  long long
#define PII  pair<int, int>
using namespace std;
int dir[5][2] = { { 0,1 } ,{ 0,-1 },{ 1,0 },{ -1,0 } ,{ 0,0 } };
const long long INF = 0x7f7f7f7f7f7f7f7f;
const int inf = 0x3f3f3f3f;
const double pi = 3.14159265358979;
const int mod = 1e9 + 7;
const int N = 1005;
//if(x<0 || x>=r || y<0 || y>=c)
//1000000000000000000

inline ll read()
{
    ll x = 0; bool f = true; char c = getchar();
    while (c < ‘0‘ || c > ‘9‘) { if (c == ‘-‘) f = false; c = getchar(); }
    while (c >= ‘0‘ && c <= ‘9‘) x = (x << 1) + (x << 3) + (c ^ 48), c = getchar();
    return f ? x : -x;
}

int n, m;
int g[N][N];
vector<int> d(N, -inf);
int dijkstra()
{
    vector<bool> vis(N, false);
    for (int i = 1; i <= n; i++)
        d[i] = g[i][1];
    d[1] = 0;
    vis[1] = 1;
    for (int i = 1; i < n; i++)
    {
        int maxi = -1, maxn = 0;
        for (int j = 1; j <= n; j++)//目前1到各点最少的承重是minn，这个节点是mini
        {
            if (!vis[j] && d[j]>maxn)
            {
                maxi = j;
                maxn = d[j];
            }
        }
        if (maxi == -1)
            break;
        vis[maxi] = 1;
        for (int j = 1; j <= n; j++)//更新d[j]（1到mini的这条线路）
        {
            if (!vis[j])
            {
                d[j] = max(d[j],min(maxn, g[j][maxi]));
            }
        }
    }
    return d[n];
}

int main() 
{
    int T;
    cin >> T;
    for (int t = 1; t <= T; t++)
    {
        printf("Scenario #%d:\n", t);
        cin >> n >> m;
        memset(g,0,sizeof(g));
        for (int i = 1; i <= m; i++)
        {
            int u, v, w;
            cin >> u >> v >> w;
            g[u][v] = w;
            g[v][u] = w;
        }
        cout << dijkstra() << endl;
        cout << endl;
    }
    return 0;
}