Submission #671502

#	Time	Username	Problem	Language	Result	Execution time	Memory
671502		amunduzbaev	Sparklers (JOI17_sparklers)	C++17	50 / 100	45 ms	8268 KiB

sparklers

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

#define ar array
typedef long long ll;
#define int ll

const int N = 1e3 + 5;
int x[N], dp[N][N];

signed main(){
	ios::sync_with_stdio(0); cin.tie(0);
	
	int n, k, T; cin >> n >> k >> T;
	for(int i=1;i<=n;i++){
		cin >> x[i];
	}
	
	x[n + 1] = x[n];
	
	auto check = [&](int s){
		int t = T * s * 2;
		memset(dp, 0, sizeof dp);
		dp[k][k] = 1;
		for(int d=0;d<n;d++){
			for(int l=1, r=1+d;l+d<=n;l++, r++){
				if(!dp[l][r]) continue;
				if(1 < l && (r - l + 1) * t >= x[r] - x[l - 1]){
					dp[l - 1][r] = 1;
				} 
				if(r < n && (r - l + 1) * t >= x[r + 1] - x[l]){
					dp[l][r + 1] = 1;
				}
			}
		}
		
		return dp[1][n];
	};
	
	int l = 0, r = x[n] / (T * 2) + 1;
	while(l < r){
		int m = (l + r) >> 1;
		if(check(m)) r = m;
		else l = m + 1;
	}
	
	cout<<l<<"\n";
}

• Subtask 1: 30 / 30
• Subtask 2: 20 / 20
• Subtask 3: 0 / 50