Submission #714762

#	Time	Username	Problem	Language	Result	Execution time	Memory
714762		ajab_01	Toll (BOI17_toll)	C++17	0 / 100	145 ms	239220 KiB

toll

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

const int INF = 1e9;
const int N = 1e4 + 1;
const int O = 3e3 + 1;
vector<pair<int , int> > g[N] , query;
priority_queue<pair<int , int> > pq;
vector<int> vec;
int dp[N][O] , ind[N] , val[N] , pre[N] , pr[N] , k , n , m , o;
bool mark[N] , vis[N] , ch = 1;

void dijkstra(){
	val[0] = 0;
	pq.push({0 , 0});
	while(!pq.empty()){
		int v = pq.top().second;
		pq.pop();
		if(vis[v]) continue;
		vis[v] = 1;
		for(auto i : g[v]){
			int u = i.first , w = i.second;
			if(val[u] > val[v] + w){
				val[u] = val[v] + w;
				pq.push({-val[u] , u});
			}
		}
	}
}

int main(){
	ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);
	memset(pr , -1 , sizeof(pr));
	fill(val , val + N , INF);
	memset(dp , -1 , sizeof(dp));
	cin >> k >> n >> m >> o;
	for(int i = 0 ; i < m ; i++){
		int u , v , w;
		cin >> u >> v >> w;
		g[u].push_back({v , w});
	}

	for(int i = 0 ; i < o ; i++){
		int a , b;
		cin >> a >> b;
		query.push_back({a , b});
		if(a) ch = 0;
		if(mark[b]) continue;
		vec.push_back(b);
		ind[b] = (int)vec.size() - 1;
		mark[b] = 1;
	}

	if(k == 1){
		int bef = 0;
		for(int i = 0 ; i < n ; i++){
			if(i == bef)
				pre[i] = 0;
			else
				pre[i] = pre[i - 1] + g[i - 1][0].second;
			pr[i] = bef;
			if(!g[i].size()){
				while(!g[i].size())i++;
				bef = i;
				i--;
			}
		}
		for(auto i : query){
			if(pr[i.first] == -1 || pr[i.second] == -1 || pr[i.first] != pr[i.second] || i.second < i.first)
				cout << -1 << '\n';
			else
				cout << pre[i.second] - pre[i.first] << '\n';
		}
		return 0;
	}

	if(ch){
		dijkstra();
		for(auto i : query){
			if(val[i.second] == INF)
				cout << -1 << '\n';
			else
				cout << val[i.second] << '\n';
		}
		return 0;
	}

	if(o <= 3000){
		int sz = (int)vec.size();
		for(int i = 0 ; i < sz ; i++)
			dp[vec[i]][i] = 0;

		for(int v = n - 1 ; v >= 0 ; v--){
			for(int j = 0 ; j < sz ; j++){
				for(auto u : g[v]){
					if(dp[u.first][j] == -1) continue;
					if(dp[v][j] == -1)
						dp[v][j] = dp[u.first][j] + u.second;
					else 
						dp[v][j] = min(dp[v][j] , dp[u.first][j] + u.second);
				}
			}
		}

		for(auto i : query){
			int a = i.first , b = i.second;
			if(dp[a][ind[b]] == -1)
				cout << -1 << '\n';
			else
				cout << dp[a][ind[b]] << '\n';
		}
		return 0;
	}
	cout << "jalebe" << '\n';
	return 0;
}

• Subtask 1: 0 / 7
• Subtask 2: 0 / 10
• Subtask 3: 0 / 8
• Subtask 4: 0 / 31
• Subtask 5: 0 / 44