Submission #770591

#	Time	Username	Problem	Language	Result	Execution time	Memory
770591		Blagoj	Robot (JOI21_ho_t4)	C++17	100 / 100	696 ms	99264 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()
 
struct Node {
    ll to, color, cost;
};
 
unordered_map<int, vector<Node>> edg[100005];
unordered_map<int, ll> sum[100005], dp2[100005];
ll dp[100005];
int n, m;
 
struct T {
    ll dist, place, color;
};
 
bool operator<(T a, T b) { return a.dist > b.dist; }
 
void solve() {
    priority_queue<T> pq;
    pq.push({0, 1, 0});
    while (pq.size() > 0) {
        T top = pq.top();
        pq.pop();
        if (top.color) {
            if (top.dist != dp2[top.place][top.color]) continue;
            for (auto [to, color, cost] : edg[top.place][top.color]) {
                ll newCost = top.dist + sum[top.place][color] - cost;
                if (newCost < dp[to]) {
                    dp[to] = newCost;
                    pq.push({dp[to], to, 0});
                }
            }
            continue;
        }
        if (top.dist != dp[top.place]) continue;
        for (auto x : edg[top.place]) {
            for (auto [to, color, cost] : x.second) {
                ll newCost = top.dist + min(cost, sum[top.place][color] - cost);
                if (newCost < dp[to]) {
                    dp[to] = newCost;
                    pq.push({dp[to], to, 0});
                }
                if (!dp2[to].count(color) || top.dist < dp2[to][color]) {
                    dp2[to][color] = top.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++) {
        ll 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