Submission #889214

#	Time	Username	Problem	Language	Result	Execution time	Memory
889214		Minbaev	Railway Trip (JOI17_railway_trip)	C++17	20 / 100	2049 ms	17356 KiB

railway_trip

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#pragma GCC target("avx,avx2,fma")
#pragma GCC optimize("Ofast,unroll-loops")
#define pii pair<int,int>
using namespace __gnu_pbds;
using namespace std;
#define pb push_back
#define all(x) x.begin(),x.end()
#define rall(x) x.rbegin(),x.rend()
#define int long long
#define f first
#define s second
#define pii pair<int,int>
template<class T>bool umax(T &a,T b){if(a<b){a=b;return true;}return false;}
template<class T>bool umin(T &a,T b){if(b<a){a=b;return true;}return false;}
typedef tree<int, null_type, less_equal<int>, rb_tree_tag,
	tree_order_statistics_node_update> ordered_set;
const int mod= 1e9 +7;
const int N=1e5*4;

int binpow (int a, int n) {
	if (n == 0)
		return 1;
	if (n % 2 == 1)
		return binpow (a, n-1) * a;
	else {
		int b = binpow (a, n/2);
		return b * b;
	}
}

vector<int>g[N];
	int n,m,k,q;

void bfs(int x,int y){
	vector<int>dist(n+1,mod);
	dist[x] = 0;
	queue<int>q;
	q.push(x);
	while(!q.empty()){
		auto ind = q.front();
		q.pop();
		
		for(auto to:g[ind]){
			if(umin(dist[to],dist[ind] + 1)){
				q.push(to);
			}
		}
		
	}
	cout<<dist[y] - 1<<"\n";	
	
}

void solve(){

	cin>>n>>m>>q;
	
	vector<int>a(n+1);
	for(int i = 1;i<=n;i++){
		cin>>a[i];
	}
	
	for(int i = 0 ; i <= n;i++){
		int mx = 0;
		for(int j = i + 1;j<=n;j++){
			if(umax(mx,a[j])){
				g[i].pb(j);
				g[j].pb(i);	
			}
			if(mx>=a[i])break;
		}
	}
	while(q--){
		int x,y;
		cin>>x>>y;
		bfs(x,y);
	}









}

 signed main()
{
//	freopen("seq.in", "r", stdin);
//  freopen("seq.out", "w", stdout);
	ios_base::sync_with_stdio(0);cin.tie(NULL);cout.tie(NULL);
	int cnt=0;
	int tt=1;//cin>>tt;
	while(tt--)solve();

}

• Subtask 1: 5 / 5
• Subtask 2: 15 / 15
• Subtask 3: 0 / 25
• Subtask 4: 0 / 55