北京大学机试 I Wanna Go Home 需要二刷 *最短路径衍生问题

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

const int maxn = 700;
const int INF = 1000000;

int n;
int m;

int ma[maxn][maxn];
bool vis[maxn];
int camp[maxn];
int dis[maxn];

void init() {
    fill(vis, vis + maxn, false);
    fill(camp, camp + maxn, 0);
    fill(dis, dis+maxn, INF);
    fill(ma[0], ma[0] + maxn * maxn, INF);
}

void dij(int st) {
    dis[st] = 0;
    for (int u = 0; u < n; u++) {
        int index = -1;
        int Min = INF;
        for (int i = 1; i <= n; i++) {
            if (!vis[i] && dis[i] < Min) {
                index = i;
                Min = dis[i];
            }
        }
        if (index == -1)
            return;
        vis[index] = true;
        for (int i = 1; i <= n; i++) {
            if (camp[index] == 1) {
                if (!vis[i] && ma[index][i] != INF && dis[i] > ma[index][i] + dis[index]) {
                    dis[i] = ma[index][i] + dis[index];
                }
            }
            else {
                if (!vis[i] && ma[index][i] != INF && dis[i] > ma[index][i] + dis[index]&&camp[i]==2) {
                    dis[i] = ma[index][i] + dis[index];
                }
            }
        }
    }
}

int main() {
    while (cin >> n) {
        if (n == 0)
            break;
        init();
        int a, b, d;
        cin >> m;
        for (int i = 0; i < m; i++) {
            cin >> a >> b >> d;
            if(d<ma[a][b])
                ma[a][b] = ma[b][a] = d;
        }
        for (int i = 1; i <= n; i++) {
            cin >> camp[i];
        }
        dij(1);
        if (dis[2] != INF)
            cout << dis[2] << endl;
        else
            cout << -1 << endl;
    }
}