Submission #516399

#	Time	Username	Problem	Language	Result	Execution time	Memory
516399		XII	Robot (JOI21_ho_t4)	C++17	100 / 100	977 ms	86756 KiB

Main

#include <bits/stdc++.h>
using namespace std;

using ll = long long;

#define fi first
#define se second
#define mp make_pair
#define eb emplace_back
#define ALL(x) (x).begin(), (x).end()

#define FOR(i, a, b) for(int i = (a); i < (b); ++i)
#define FORU(i, a, b) for(int i = (a); i <= (b); ++i)
#define FORD(i, a, b) for(int i = (a); i >= (b); --i)

#define IOS cin.tie(0)->sync_with_stdio(false);
#define PROB "JOI21_ho_t4"
void Fi(){
    if(fopen(PROB".inp", "r")){
        freopen(PROB".inp", "r", stdin);
        freopen(PROB".out", "w", stdout);
    }
}

const int N = 1e5 + 1;
const ll INF = 1e18;
int n, m;
using pi = pair<int, int>;
map<int, vector<pi>> adj[N];
map<int, ll> tot[N], dp2[N];
map<int, ll> dp[N];

using T = pair<ll, pair<int, int>>;
priority_queue<T, vector<T>, greater<T>> pq;

ll dijkstra(const int &s, const int &e){
    FORU(i, 1, n) dp[i][0] = INF;
    pq.emplace(0, mp(s, 0));
    dp[s][0] = 0;
    while(!pq.empty()){
        ll wu = pq.top().fi;
        auto [u, cu] = pq.top().se;
        pq.pop();
        if(cu){
            if(dp2[u][cu] != wu) continue;
            for(auto [v, wv]: adj[u][cu]){
                ll w = wu + (tot[u][cu] - wv);
                if(dp[v][0] > w){
                    dp[v][0] = w;
                    pq.emplace(dp[v][0], mp(v, 0));
                }
            }
        } else{
            if(dp[u][0] != wu) continue;
            for(auto [cv, ed]: adj[u]){
                for(auto [v, wv]: ed){
                    ll case1 = wu + wv;
                    if(dp[v][0] > case1){
                        dp[v][0] = case1;
                        pq.emplace(dp[v][0], mp(v, 0));
                    }
                    ll case2 = wu + (tot[u][cv] - wv);
                    if(dp[v][0] > case2){
                        dp[v][0] = case2;
                        pq.emplace(dp[v][0], mp(v, 0));
                    }
                    ll case3 = wu;
                    if(!dp2[v].count(cv) || dp2[v][cv] > case3){
                        dp2[v][cv] = case3;
                        pq.emplace(dp2[v][cv], mp(v, cv));
                    }
                }
            }
        }
    }
    return (dp[e][0] == INF ? -1 : dp[e][0]);
}

int main(){
    IOS;
    Fi();
    cin >> n >> m;
    FORU(i, 1, m){
        int u, v, c, p;
        cin >> u >> v >> c >> p;
        adj[u][c].eb(v, p);
        adj[v][c].eb(u, p);
        tot[u][c] += p;
        tot[v][c] += p;
    }
    cout << dijkstra(1, n);
    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'void Fi()':
Main.cpp:20:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   20 |         freopen(PROB".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:21:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   21 |         freopen(PROB".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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