Submission #1129883

#	Time	Username	Problem	Language	Result	Execution time	Memory
1129883		agrim_09	Olympic Bus (JOI20_ho_t4)	C++20	5 / 100	1096 ms	9528 KiB

ho_t4

// #pragma GCC optimize("O3,unroll-loops")
// #pragma GCC target("avx2,bmi,bmi2,lzcnt,popcnt")
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
using namespace std;
using namespace __gnu_pbds;
template <class T>
using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
#define endl '\n';
#define fastio ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define py cout << "YES" << endl;
#define pn cout << "NO" << endl;
#define pb push_back
#define int long long
typedef long double lld;
#define double lld
typedef long long ll;
typedef unsigned long long ull;
const ll inf = 1e18;
const ll mod = 1e9+7;
const int N = 2e5;
vector<int>primes = {2,3,5,7,11,13,17,19,23,29,31,37,41,43,47,53,59,61,67,71,73,79,83,89,97};

// Check for queue, priorioty_queue, stack, ordered_set solutions
// stack => LIFO (whatever goes in last comes out last)
// queue => FIFO (whatever goes in first comes out first)
// priority_queue => Dynamic queries of minimum/maximum
// ordered_set => set in vector form
//[order_of_key(k) gives number of elements less than k, while find_by_order(i) gives i^th element]

// To comment multiple lines : ctrl + /
// To find and replace : ctrl+H

void judge(){
    srand(time(NULL));
    #ifndef ONLINE_JUDGE
    freopen("inputB.txt","r",stdin);
    freopen("outputB.txt","w",stdout);
    freopen("Error.txt", "w", stderr);
    #define debug(x...) cerr << #x <<" = "; _print(x); cerr << endl;
    #else
    #define debug(x...)
    #endif
}

void usaco(string s) {
    freopen((s + ".in").c_str(),"r",stdin);
    freopen((s + ".out").c_str(),"w",stdout);
}

int dijkstra(vector<vector<pair<int,ll>>>&adj, vector<int>src){
    int n = adj.size();
    vector<ll>dist(n,inf);
    priority_queue<pair<ll,int>>pq;
    for(auto source : src){
        dist[source] = 0;
        pq.push({0,source});
    }
    
    while(!pq.empty()){
        auto x = pq.top();
        ll d = -1*x.first; int node = x.second;
        pq.pop();
        
        if(d!=dist[node]){
            continue;
        }
        for(auto child : adj[node]){
            int v = child.first; ll w = child.second;
            if((d+w)<dist[v]){
                dist[v] = d+w;
                pq.push({-1*(d+w),v});
            }
        }
    }
    return dist[0]+dist[n-1];
}

signed main(){
    fastio; //judge();
    int n,m; cin >> n >> m;
    vector<pair<int,int>> cost[n][n], invert[n][n];
    
    vector<vector<int>>type(m);
    for(int i = 0,u,v,c,d;i<m;i++){
        cin >> u >> v >> c >> d; u--; v--;
        cost[u][v].pb({c,i}); 
        invert[u][v].pb({d,i});
        type[i] = {u,v,c,d};
    }
    
    // for(int i = 0;i<n;i++){
    //     for(int j = 0;j<n;j++){
    //         if(cost[i][j].size()==0){
    //             continue;
    //         }

    //     }
    // }
    int best = inf;
    vector<vector<int>>matrix2(n,vector<int>(n,inf));
    for(int j = 0;j<m;j++){
        matrix2[type[j][0]][type[j][1]] = min(matrix2[type[j][0]][type[j][1]],type[j][2]);
    }
    vector<vector<pair<int,int>>>adj2(n);
    for(int x = 0;x<n;x++){
        for(int y = 0;y<n;y++){
            if(matrix2[x][y]!=inf){
                adj2[x].pb({y,matrix2[x][y]});
            }
        }
    }
    best = min(best,dijkstra(adj2,{0}) + dijkstra(adj2,{n-1}));
    for(int i = 0;i<m;i++){
        vector<vector<int>>matrix(n,vector<int>(n,inf));
        int cost = type[i][3];
        for(int j = 0;j<i;j++){
            matrix[type[j][0]][type[j][1]] = min(matrix[type[j][0]][type[j][1]],type[j][2]);
        }
        for(int j = i+1;j<m;j++){
            matrix[type[j][0]][type[j][1]] = min(matrix[type[j][0]][type[j][1]],type[j][2]);
        }
        matrix[type[i][1]][type[i][0]] = min(matrix[type[i][1]][type[i][0]],type[i][2]);
        
        vector<vector<pair<int,int>>>adj(n);
        for(int x = 0;x<n;x++){
            for(int y = 0;y<n;y++){
                if(matrix[x][y]!=inf){
                    adj[x].pb({y,matrix[x][y]});
                }
            }
        }
        best = min(best,cost+dijkstra(adj,{0})+dijkstra(adj,{n-1}));
        // if(i==1){
        //     cout << dijkstra(adj,{0}) << endl;
        // }
        
    }
    if(best==inf){
        cout << -1;
    }
    else{
        cout << best;
    }
}

Compilation message (stderr)

ho_t4.cpp: In function 'void judge()':
ho_t4.cpp:37:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   37 |     freopen("inputB.txt","r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
ho_t4.cpp:38:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   38 |     freopen("outputB.txt","w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
ho_t4.cpp:39:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   39 |     freopen("Error.txt", "w", stderr);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
ho_t4.cpp: In function 'void usaco(std::string)':
ho_t4.cpp:47:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   47 |     freopen((s + ".in").c_str(),"r",stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ho_t4.cpp:48:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   48 |     freopen((s + ".out").c_str(),"w",stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 5 / 5
• Subtask 2: 0 / 11
• Subtask 3: 0 / 21
• Subtask 4: 0 / 63