Submission #1291044

#	Time	Username	Problem	Language	Result	Execution time	Memory
1291044		Jawad_Akbar_JJ	Robot (JOI21_ho_t4)	C++20	0 / 100	54 ms	28580 KiB

Main

#include <iostream>
#include <map>
#include <set>
#include <vector>

using namespace std;
const int N = 1<<18;
vector<pair<int,int>> nei[N];
int c[N], p[N], inf = 1e9;
map<int,int> dp[N>>1], Sum[N>>1];

void dijkstra(int u){
	for (int i=2;i<N;i++)
		dp[i][0] = inf;

	dp[1][0] = 0;
	set<pair<int,pair<int,int>>> st = {{0, {1, 0}}};

	while (st.size() > 0){
		auto [mn, pr] = *st.begin();
		auto [u, cl] = pr;
		st.erase(begin(st));

		if (mn != dp[u][cl])
			continue;

		for (auto [i, id] : nei[u]){
			if (cl != 0 and c[id] != cl)
				continue;

			// int v1 = mn, v2 = dp[i][cl], v3 = dp[i][0], v4 = Sum[u][cl];
			if (cl == 0){
				if (dp[i][0] > dp[u][0] + min(p[id], Sum[u][c[id]] - p[id]))
					dp[i][0] = dp[u][0] + min(p[id], Sum[u][c[id]] - p[id]), st.insert({dp[i][0], {i, 0}});
				if (dp[i][c[id]] > dp[u][0])
					dp[i][c[id]] = dp[u][0], st.insert({dp[i][c[id]], {i, c[id]}});
			}
			else{
				if (dp[i][0] > dp[u][cl] + Sum[u][cl] - p[id])
					dp[i][0] = dp[u][cl] + Sum[u][cl] - p[id], st.insert({dp[i][0], {i, 0}});
			}
		}
	}
}

int main(){
	ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
	int n, m;
	cin>>n>>m;

	for (int i=1, a, b;i<=m;i++){
		cin>>a>>b>>c[i]>>p[i];
		nei[a].push_back({b, i});
		nei[b].push_back({a, i});

		Sum[a][c[i]] += p[i];
		Sum[b][c[i]] += p[i];
		dp[ a][c[i]] = dp[b][c[i]] = inf;
	}

	dijkstra(1);

	cout<<dp[n][0]<<'\n';
}

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