Submission #770590

#	Time	Username	Problem	Language	Result	Execution time	Memory
770590		Blagoj	Robot (JOI21_ho_t4)	C++17	100 / 100	787 ms	92924 KiB

Main

#include <bits/stdc++.h>
 
#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#endif
 
#pragma GCC optimize("Ofast,unroll-loops")
 
using namespace std;
 
#define endl '\n'
#define ll long long
#define all(x) x.begin(), x.end()
 
map<int, vector<tuple<int, int, int>>> edg[100005];
unordered_map<int, ll> sum[100005], dp2[100005];
ll dp[100005];
int n, m;
 
void solve() {
    priority_queue<tuple<ll, int, int>> pq;
    pq.push({0, 1, 0});
    while (pq.size() > 0) {
        ll dist;
        int place, color;
        tie(dist, place, color) = pq.top();
        dist *= -1;
        pq.pop();
        if (color) {
            if (dist != dp2[place][color]) continue;
            for (auto [to, color, cost] : edg[place][color]) {
                ll newCost = dist + sum[place][color] - cost;
                if (newCost < dp[to]) {
                    dp[to] = newCost;
                    pq.push({-dp[to], to, 0});
                }
            }
        }
        else {
            if (dist != dp[place]) continue;
            for (auto x : edg[place]) {
                for (auto [to, color, cost] : x.second) {
                    ll newCost = dist + min((ll) cost, sum[place][color] - (ll) cost);
                    if (newCost < dp[to]) {
                        dp[to] = newCost;
                        pq.push({-dp[to], to, 0});
                    }
                    if (!dp2[to].count(color) || dist < dp2[to][color]) {
                        dp2[to][color] = dist;
                        pq.push({-dp2[to][color], to, color});
                    }
                }
            }
        }
    }
    cout << ((dp[n] == LLONG_MAX) ? -1 : dp[n]);
}
 
int main() {
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cin >> n >> m;
    for (int i = 2; i <= n; i++) dp[i] = LLONG_MAX;
    for (int i = 0; i < m; i++) {
        int from, to, color, cost;
        cin >> from >> to >> color >> cost;
        edg[from][color].push_back({to, color, cost});
        edg[to][color].push_back({from, color, cost});
        sum[from][color] += cost;
        sum[to][color] += cost;
    }
    solve();
}

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