Submission #1023279

#	Time	Username	Problem	Language	Result	Execution time	Memory
1023279		KhoaDuy	Robot (JOI21_ho_t4)	C++14	100 / 100	954 ms	120056 KiB

Main

#include <bits/stdc++.h>
using namespace std;
#define int long long
#define endl '\n'
struct node{
    int u,c,w;
};
struct cmp{
    bool operator()(node &a,node &b){
        return (a.w>b.w);
    }
};
struct edge{
    int v,c,p;
};
signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int n,m;
    cin >> n >> m;
    vector<map<int,int>> bst(n+1);
    vector<map<int,vector<edge>>> graph(n+1);
    vector<map<int,int>> Pre(n+1);
    vector<map<int,bool>> vis(n+1);
    for(int i=0;i<m;i++){
        int a,b,c,p;
        cin >> a >> b >> c >> p;
        graph[a][c].push_back({b,c,p});
        graph[b][c].push_back({a,c,p});
        Pre[a][c]+=p;
        Pre[b][c]+=p;
    }
    priority_queue<node,vector<node>,cmp> pq;
    bst[1][0]=0;
    pq.push({1,0,0});
    while(!pq.empty()){
        node curr=pq.top();
        pq.pop();
        if(bst[curr.u][curr.c]<curr.w||vis[curr.u][curr.c]){
            continue;
        }
        vis[curr.u][curr.c]=true;
        if(curr.c){
            for(edge x:graph[curr.u][curr.c]){
                int dist=curr.w+Pre[curr.u][curr.c]-x.p;
                if(bst[x.v].find(0)==bst[x.v].end()||bst[x.v][0]>dist){
                    bst[x.v][0]=dist;
                    pq.push({x.v,0,dist});
                }
            }
        }
        else{
            for(pair<const int,vector<edge>> temp:graph[curr.u]){
                for(edge x:temp.second){
                    int dist=curr.w+min(x.p,Pre[curr.u][x.c]-x.p);
                    if(bst[x.v].find(0)==bst[x.v].end()||bst[x.v][0]>dist){
                        bst[x.v][0]=dist;
                        pq.push({x.v,0,dist});
                    }
                    dist=curr.w;
                    if(bst[x.v].find(x.c)==bst[x.v].end()||bst[x.v][x.c]>dist){
                        bst[x.v][x.c]=dist;
                        pq.push({x.v,x.c,dist});
                    }
                }
            }
        }
    }
    if(bst[n].find(0)==bst[n].end()){
        cout << -1;
    }
    else{
        cout << bst[n][0];
    }
}

• Subtask 1: 34 / 34
• Subtask 2: 24 / 24
• Subtask 3: 42 / 42