Submission #443965

#	Time	Username	Problem	Language	Result	Execution time	Memory
443965		Khizri	Watching (JOI13_watching)	C++17	0 / 100	1 ms	460 KiB

watching

#include <bits/stdc++.h>
using namespace std;
//------------------------------DEFINE------------------------------
//******************************************************************
#define IOS ios_base::sync_with_stdio(false); cin.tie(0),cout.tie(0)
#define ll long long
#define pb push_back		 
#define F first																 
#define S second 															 
#define INF 1e18
#define all(v) (v).begin(),(v).end()
#define rall(v) (v).rbegin(),(v).rend()
#define pii pair<int,int>
#define pll pair<ll,ll>
#define OK cout<<"Ok"<<endl;
#define MOD (ll)(1e9+7)
#define endl "\n"
//******************************************************************
//----------------------------FUNCTION------------------------------
//******************************************************************
ll gcd(ll a,ll b){
	if(a>b) swap(a,b);
	if(a==0) return a+b;
	return gcd(b%a,a);
}
ll lcm(ll a,ll b){
	return a/gcd(a,b)*b;
}
bool is_prime(ll n){
	ll k=sqrt(n);
	if(n==2) return true;
	if(n<2||n%2==0||k*k==n) return false;
	for(int i=3;i<=k;i+=2){
		if(n%i==0){
			return false;
		}
	}
	return true;
}
//*****************************************************************
//--------------------------MAIN-CODE------------------------------
const int mxn=100+5;
ll t=1,n,arr[mxn],a,b,color[mxn];
vector<ll>vt;
ll cal(int ind,ll dis){
	return lower_bound(vt.begin(),vt.end(),vt[ind]+dis-1)-vt.begin()-1;
}
bool check(int x,int y,ll dis){
	vector<vector<int>>dp(n+5,vector<int>(n+5,0));
	dp[0][0]=0;
	if(x>0){
		dp[1][0]=cal(dp[0][0],dis);
	}
	if(y>0){
		dp[0][1]=cal(dp[0][0],2*dis);
	}
	for(int i=1;i<=x;i++){
		for(int j=1;j<=y;j++){
			dp[i][j]=max(cal(dp[i-1][j],dis),cal(dp[i][j-1],2*dis));
		}
	}
	if(dp[x][y]==n-1){
		return true;
	}
	return false;
}
void solve(){
	cin>>n>>a>>b;
	for(int i=1;i<=n;i++){
		cin>>arr[i];
		vt.pb(arr[i]);
	}
	sort(all(vt));
	ll l=0,r=1e9,k=0;
	while(l<=r){
		ll m=(l+r)/2;
		if(check(a,b,m)){
			r=m-1;
			k=m;
		}
		else{
			l=m+1;
		}
	}
	cout<<k/2<<endl;
}
int main(){
	IOS;
	//cin>>t;
	while(t--){
		solve();
	}
	return 0;
}

• Subtask 1: 0 / 50
• Subtask 2: 0 / 50