LCP 35. 电动车游城市（分层图最短路+Dijkstra）

leedcode测试链接：https://leetcode.cn/problems/DFPeFJ/

题解：

class Solution {
public:
    int electricCarPlan(vector<vector<int>>& paths, int cnt, int start, int end, vector<int>& charge) {
        int n = charge.size();
        vector<vector<pair<int,int>>>graph(n);
        vector<vector<bool>>vis(n,vector<bool>(cnt+1,false));
        priority_queue<vector<int>,vector<vector<int>>,greater<vector<int>>>pq;
        vector<vector<int>>dis(n,vector<int>(cnt+1,INT_MAX));
        for(int i=0;i<paths.size();i++)
        {
            int u = paths[i][0];
            int v = paths[i][1];
            int w = paths[i][2];
            graph[u].push_back({v,w});
            graph[v].push_back({u,w});
        }
        pq.push({0,0,start});
        while(!pq.empty())
        {
            vector<int> node = pq.top();
            pq.pop();
            int cost = node[0];
            int pow = node[1];
            int cur = node[2];
            if(vis[cur][pow])continue;
            if(cur==end)return cost;
            if(pow<cnt&&!vis[cur][pow+1]&&charge[cur]+cost<dis[cur][pow+1])
            {
                dis[cur][pow+1] = charge[cur] + cost;
                pq.push({dis[cur][pow+1],pow+1,cur});
            }
            vis[cur][pow]=true;
            for(auto edge:graph[cur])
            {
                int nt = edge.first;
                int rpow = pow - edge.second;
                int ct = cost+edge.second;
                if(rpow>=0&&!vis[nt][rpow]&&ct<dis[nt][rpow])
                {
                    dis[nt][rpow]=ct;
                    pq.push({ct,rpow,nt});
                }
            }
        }
        return -1;
    }
};