kuangbin_ShortPath N (POJ 1847)

模板题辣很简单的 只有两种val 0 和1

#include <iostream>
#include <string>
#include <cstdio>
#include <cmath>
#include <cstring>
#include <queue>
#include <vector>
#include <set>
#include <algorithm>
#define INF 0x3F3F3F3F
using namespace std;

typedef pair<int, int> pii;
struct cmp{
    bool operator () (const pii a, const pii b){
        return a.first > b.first;
    }
};

int val[110][110];
int n, a, b;

int dij()
{
    int  dist[110];
    priority_queue<pii, vector<pii>, cmp> q;
    memset(dist, 0x3f, sizeof dist);
    dist[a] = 0;
    q.push(make_pair(0, a));
    while(!q.empty()){
        pii u = q.top();
        q.pop();
        //printf("u.second = %d
", u.second);
        if(u.first > dist[u.second]) continue;
        for(int i = 1; i <= n; i++){
            if(dist[i] > dist[u.second] + val[u.second][i]){
                dist[i] = dist[u.second] + val[u.second][i];
                q.push(make_pair(dist[i], i));
            }
        }
    }
    return dist[b] == INF ? -1 : dist[b];
}

int main()
{
    memset(val, 0x3f, sizeof val);
    scanf("%d%d%d", &n, &a, &b);
    for(int i = 1; i <= n; i++){
        int m, to;
        scanf("%d", &m);
        if(m == 0) continue;
        m--;
        scanf("%d", &to);
        val[i][to] = 0;
        while(m--){
            scanf("%d", &to);
            val[i][to] = 1;
        }
    }
    printf("%d
", dij());
    return 0;
}