Submission #974644

#	Time	Username	Problem	Language	Result	Execution time	Memory
974644		berr	Robot (JOI21_ho_t4)	C++17	0 / 100	3117 ms	799868 KiB

Main

#include <bits/stdc++.h>
using namespace std; 
#define int long long
const int N=5005, INF=1e18;
 
signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
   
    int n, m; cin >> n >> m;
 
    vector<vector<array<int, 2>>> g(n);
    vector<int> c(m), p(m), id(m), u(m), v(m);
    vector<int> pos_u(m), pos_v(m);
 
    for(int i=0; i<m; i++){
        cin >> u[i] >> v[i] >> c[i] >> p[i];
        u[i]--; v[i]--;
 
        if(u[i] > v[i]) swap(u[i], v[i]);
        g[u[i]].push_back({v[i], i});
        g[v[i]].push_back({u[i], i});
 
        
    }
 
    for(int i=0; i<n; i++){
        sort(g[i].begin(), g[i].end(), [&](auto x, auto y){
            return c[x[1]]<c[y[1]];
        });
 
        for(int l=0; l<g[i].size(); l++){
            auto [u, j]=g[i][l];
            if(i<u) pos_u[j] = l;
            else pos_v[j] = l;
        }
    }
 
    priority_queue<array<int, 3>> pq;
    pq.push({0, 0, -1});
    vector<int> dp(n, INF);
    map<int, int> dpp[n];
    int ans = INF;
    dp[0]=0;
    while(pq.size()){
        auto [cost, ve, z] = pq.top();
 
        pq.pop(); 
        cost*=-1;
 
        if(ve==n-1){ 
            ans=min(ans, cost);
            break;
        }
        int h=1;
        if(z==-1){

            if(dp[ve]!=cost) continue;
 
            int k=1;
 
            for(auto [i, j]: g[ve]){
                if(!dpp[i].count(c[j])||dpp[i][c[j]]>cost+p[j]){
                    dpp[i][c[j]]=cost+p[j];
                    pq.push({-(cost+p[j]), i, j});
                }
                if(dp[i]>cost+p[j]){
                    dp[i]=cost+p[j];
                    pq.push({-dp[i], i, -1});
                }
            }
            if(g[ve].size()){
                int tot=p[g[ve][0][1]];
     
                for(int l=1; l<g[ve].size(); l++){
                    if(c[g[ve][l][1]]==c[g[ve][l-1][1]]){
                            k++;
                            tot+=p[g[ve][l][1]];
                        }
                        else{
                            for(int j=l-k; j<l; j++){
                                 if(dp[g[ve][j][0]] > min(tot-p[g[ve][j][1]], p[g[ve][j][1]])){
                                    dp[g[ve][j][0]] =cost+tot-p[g[ve][j][1]];
                                    pq.push({-(cost+min(tot-p[g[ve][j][1]], p[g[ve][j][1]])), g[ve][j][0], -1});
                                }                        
                            }
                            tot=p[g[ve][l][1]];
                            k=1;
                        }
                    }
     
                    for(int j=g[ve].size()-k; j<g[ve].size(); j++){
                        if(dp[g[ve][j][0]] > cost+tot-p[g[ve][j][1]]){
                            dp[g[ve][j][0]]=cost+tot-p[g[ve][j][1]];
                            pq.push({-(cost+tot-p[g[ve][j][1]]), g[ve][j][0], -1});
                        }
                    }
                
                }
     
        }
        else{
            if(dpp[ve][c[z]]!=cost) continue;

            int pos=0;
            if(v[z]==ve) pos=pos_v[z];
            else pos = pos_u[z];
            
         
            int count=0, id=-1;
            vector<int> aa;
            int tot=0;
            for(int i=pos-1; i>=0; i--){
                if(c[g[ve][i][1]]!=c[z]) break;
                tot+=p[g[ve][i][1]], aa.push_back(i);
            }
            for(int i=pos+1; i<g[ve].size(); i++){
                if(c[g[ve][i][1]]!=c[z]) break;
                tot+=p[g[ve][i][1]], aa.push_back(i);
            }
     
            if(aa.size()){
                for(auto l: aa){
     
                    if(dp[g[ve][l][0]]>(cost+tot-p[g[ve][l][1]])){
                        dp[g[ve][l][0]] =(cost+tot-p[g[ve][l][1]]);
                        pq.push({-(cost+tot-p[g[ve][l][1]]), g[ve][l][0], -1});
                    }
                }
            }
        }

    };
    if(ans==INF) cout<<-1;
    else cout<<ans;
 
}

Compilation message (stderr)

Main.cpp: In function 'int main()':
Main.cpp:32:23: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::array<long long int, 2> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |         for(int l=0; l<g[i].size(); l++){
      |                      ~^~~~~~~~~~~~
Main.cpp:75:31: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::array<long long int, 2> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   75 |                 for(int l=1; l<g[ve].size(); l++){
      |                              ~^~~~~~~~~~~~~
Main.cpp:92:48: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::array<long long int, 2> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   92 |                     for(int j=g[ve].size()-k; j<g[ve].size(); j++){
      |                                               ~^~~~~~~~~~~~~
Main.cpp:117:31: warning: comparison of integer expressions of different signedness: 'long long int' and 'std::vector<std::array<long long int, 2> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
  117 |             for(int i=pos+1; i<g[ve].size(); i++){
      |                              ~^~~~~~~~~~~~~
Main.cpp:110:17: warning: unused variable 'count' [-Wunused-variable]
  110 |             int count=0, id=-1;
      |                 ^~~~~
Main.cpp:110:26: warning: unused variable 'id' [-Wunused-variable]
  110 |             int count=0, id=-1;
      |                          ^~
Main.cpp:55:13: warning: unused variable 'h' [-Wunused-variable]
   55 |         int h=1;
      |             ^

• Subtask 1: 0 / 34
• Subtask 2: 0 / 24
• Subtask 3: 0 / 42