Dijkstra最短路，每次限制一个等级差，再更新答案。

#include 
     
      #define N 105#define INF 1e9int m, n;int p[N], l[N], x, t, v, g[N][N];int w, minc, d[N], u[N], ans;void Dijkstra(int q){    for(int i = 1; i <= n; i++){        d[i] = g[1][i];        if(!d[i])d[i]=INF;        u[i]=0;    }    u[1] = 1;    for(int i = 2; i <= n; i++)    {        minc = 1e9;        w = 0;        for(int j = 2; j <= n; j++)            if(!u[j] && minc >= d[j] && l[j] >= q && l[j] <= q + m)            {                minc = d[j];                w = j;            }        if(!w) break;        u[w] = 1;        for(int j = 2; j <= n; j++)            if(!u[j] && g[w][j] && d[j] > d[w] + g[w][j] && l[j] >= q && l[j] <= q + m)                d[j] = d[w] + g[w][j];    }    for(int i = 2; i <= n; i++)        if(d[i] + p[i] < ans &&l[i] >= q && l[i] <= q + m)ans = d[i] + p[i]; }int main(){    scanf("%d%d", &m, &n);    for(int i = 1; i <= n; i++)    {        scanf("%d%d%d", &p[i], &l[i], &x);        for(int j = 1; j <= x; j++)        {            scanf("%d%d", &t, &v);            g[i][t] = v;        }    }    ans = p[1];    for(int i = l[1] - m; i <= l[1] ; i++)        Dijkstra(i);    printf("%d\n",ans);    return 0;}