M - 昂贵的聘礼 最短路 dij

#include <cstdio>
#include <cstring>
#include <cstdlib>
#include <queue>
#include <vector>
#include <algorithm>
#include <iostream>
#define inf 0x3f3f3f3f
using namespace std;
const int maxn = 1e5 + 10;
struct node
{
    int to, dist, nxt;
    node(int to=0,int dist=0):to(to),dist(dist){}
}exa[maxn];
struct heapnode
{
    int u, d;
    heapnode(int u=0,int d=0):u(u),d(d){}
    bool operator<(const heapnode&a)const
    {
        return a.d < d;
    }
};
int cnt = 0;
int head[maxn];
void add(int u,int v,int w)
{
    exa[++cnt] = node(v, w);
    exa[cnt].nxt = head[u];
    head[u] = cnt;
}

int ans = 0;
int d[maxn], level[maxn], p[maxn];
bool vis[maxn];
int dij(int l,int r)
{
    memset(vis, 0, sizeof(vis));
    memset(d, inf, sizeof(d));
    d[1] = 0;
    ans = p[1];
    priority_queue<heapnode>que;
    que.push(heapnode(1, 0));
    while(!que.empty())
    {
        heapnode x = que.top(); que.pop();
        int u = x.u;
        if (vis[u]) continue;
        vis[u] = true;
        for(int i=head[u];i;i=exa[i].nxt)
        {
            node e = exa[i];
            if (level[e.to]<l || level[e.to]>r) continue;
            if(d[e.to]>d[u]+e.dist)
            {
                d[e.to] = d[u] + e.dist;
                ans = min(ans, d[e.to] + p[e.to]);
                que.push(heapnode(e.to, d[e.to]));
            }
        }
    }
    return ans;
}

int main()
{
    int m, n;
    memset(head, 0, sizeof(head));
    scanf("%d%d", &m, &n);
    for(int i=1;i<=n;i++)
    {
        int x;
        scanf("%d%d%d", &p[i], &level[i], &x);
        for(int j=1;j<=x;j++)
        {
            int a, b;
            scanf("%d%d", &a, &b);
            add(i, a, b);
        }
    }
    int ex = inf;
    for(int l=level[1],r=level[1]+m;r>=level[1];r--,l--)
    {
        ex=min(ex,dij(l, r));
    }
    printf("%d\n", ex);
    return 0;
}