Submission #1041401

#	Time	Username	Problem	Language	Result	Execution time	Memory
1041401		khanhtb	Robot (JOI21_ho_t4)	C++14	0 / 100	143 ms	27328 KiB

Main

#pragma GCC optimize("Ofast,unroll-loops")
#include <bits/stdc++.h>
#define ll long long
#define ull unsigned long long
#define ld long double
#define pb push_back
#define pf push_front
#define vi vector<ll>
#define vii vector<vi>
#define pll pair<ll, ll>
#define vpll vector<pll>
#define all(a) a.begin(), a.end()
#define fi first
#define se second
using namespace std;
const ll mod = 1e9+7; 
const ll inf = 1e18;
const ll blocksz = 320;
const ll N = 3e5+8;
ll d[N];
struct edge{
    ll v,c,w;
};
int n,m;
vector<edge> g[N];
ll dijkstra(){
    fill(d+1,d+n+1,inf);
    priority_queue<pll,vpll,greater<pll>> pq;
    pq.push({0,1});
    d[1] = 0;
    while(pq.size()){
        int u = pq.top().se, dist = pq.top().fi;
        pq.pop();
        if(dist > d[u]) continue;
        if(u == n) return dist;
        map<int,int> cnt;
        for(edge ed:g[u]){
            int v = ed.v, c = ed.c;
            ll w = ed.w;
            cnt[c] += w;
        }
        for(edge ed:g[u]){
            int v = ed.v, c = ed.c;
            ll w = ed.w;
            if(cnt[c] == w){
                if(d[v] > d[u]){
                    d[v] = d[u];
                    pq.push({d[v],v});
                }
            }
            else{
                ll cost = min(w,cnt[c]-w);
                if(d[v] > d[u]+cost){
                    d[v] = d[u]+cost;
                    pq.push({d[v],v});
                }
            }
        }
    }
    return -1;
}
void solve(){
    cin >> n >> m;
    for(int i = 1; i <= m; i++){
        int u,v,c;
        ll w;
        cin >> u >> v >> c >> w;
        g[u].pb({v,c,w});
        g[v].pb({u,c,w});
    }
    cout << dijkstra();
}
signed main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    if (fopen("test.inp", "r")) {
        freopen("test.inp", "r", stdin);
        freopen("test.out", "w", stdout);
    }   
    ll T = 1;
    // cin >> T;
    for (ll i = 1; i <= T; i++) {
        solve();
        cout << '\n';
    }
}

Compilation message (stderr)

Main.cpp: In function 'long long int dijkstra()':
Main.cpp:38:17: warning: unused variable 'v' [-Wunused-variable]
   38 |             int v = ed.v, c = ed.c;
      |                 ^
Main.cpp: In function 'int main()':
Main.cpp:78:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   78 |         freopen("test.inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:79:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   79 |         freopen("test.out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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