제출 #1364890

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1364890		khongbietdatgi	Robot (JOI21_ho_t4)	C++20	0 / 100	2145 ms	1605124 KiB

Main

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

const ll INF = 1e18;

struct Edge {
	int to, c;
	ll p;
};

map<int, vector<Edge>> graph[200005];
ll dp[200005];
map<int, ll> dp2[200005], psum[200005];

int main() {
    freopen("robot1.inp", "r", stdin);
    freopen("robot1.out", "w", stdout);
    cin.tie(0)->sync_with_stdio(0);
    int n, m;
    cin >> n >> m;
    for (int i = 1; i <= m; i++) {
        int u, v, c;
        ll p;
        cin >> u >> v >> c >> p;
        graph[u][c].push_back({v, c, p});
        graph[v][c].push_back({u, c, p});
        psum[u][c] += p;
        psum[v][c] += p;
    }

    memset(dp, 0x3f, sizeof dp);
    dp[1] = 0;
    priority_queue<tuple<ll, int, int>> pq;
    pq.push(make_tuple(0, 1, 0));
    while (pq.size()) {
        ll cost;
        int node, c;
        tie(cost, node, c) = pq.top();
        pq.pop();

        if (c) {
            if (dp2[node][c] != -cost) continue;
            for (Edge i : graph[node][c]) {
                // We can't flip i in this case
                ll case1 = psum[node][c] - i.p;
                if (case1 - cost < dp[i.to]) {
                    dp[i.to] = case1 - cost;
                    pq.push(make_tuple(-dp[i.to], i.to, 0));
                }
            }
        } else {
            if (dp[node] != -cost) continue;
            for (auto &i : graph[node]) {
                for (Edge j : i.second) {
                    // Case 1: We don't flip j
                    ll case1 = psum[node][j.c] - j.p - cost;
                    if (case1 < dp[j.to]) {
                        dp[j.to] = case1;
                        pq.push(make_tuple(-dp[j.to], j.to, 0));
                    }
                    // Case 2: We flip j but not another edge of the same colour
                    ll case2 = j.p - cost;
                    if (case2 < dp[j.to]) {
                        dp[j.to] = case2;
                        pq.push(make_tuple(-dp[j.to], j.to, 0));
                    }
                    // Case 3: We flip j and another edge of the same colour
                    ll case3 = -cost;
                    if (!dp2[j.to].count(j.c) || case3 < dp2[j.to][j.c]) {
                        dp2[j.to][j.c] = case3;
                        pq.push(make_tuple(-dp2[j.to][j.c], j.to, j.c));
                    }
                }
            }
        }
    }
    cout << (dp[n] > INF ? -1 : dp[n]);
    return 0;
}

컴파일 시 표준 에러 (stderr) 메시지

Main.cpp: In function 'int main()':
Main.cpp:17:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   17 |     freopen("robot1.inp", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:18:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   18 |     freopen("robot1.out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

• 서브태스크 1: 0 / 34
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