Submission #578445

#	Time	Username	Problem	Language	Result	Execution time	Memory
578445		Pietra	Sure Bet (CEOI17_sure)	C++14	100 / 100	171 ms	3452 KiB

sure

#include<bits/stdc++.h>
using namespace std ; 
 
const int maxn = 1e5 + 5 ; 
 
int n ; 
double x[maxn], y[maxn], p_x[maxn], p_y[maxn] ; 
 
bool cmp(double a, double b){ return a > b ; }
 
int main(){
 
    cin >> n ; 
 
    for(int i = 1 ; i <= n ; i++) cin >> x[i] >> y[i] ;  
 
    sort(x + 1, x + 1 + n, cmp) ; sort(y + 1, y + 1 + n, cmp) ; 
    
    for(int i = 1 ; i <= n ; i++) p_x[i] = p_x[i-1] + x[i], p_y[i] = p_y[i-1] + y[i] ; 
 
    double ans = 0 ; 
 
    for(int i = 1 ; i <= n ; i++){
        int ini = 1, fim = n, mid, best = 0 ; double mn = p_x[i] ; 
        while(ini <= fim){
            mid = (ini + fim)>>1 ;
            if(abs((p_x[i])-(p_y[mid])) <= mn){
                mn = abs((p_x[i])-(p_y[mid])) ; 
                best = mid ; 
            } 
            if(p_x[i] <= p_y[mid]) fim = mid - 1 ; 
            else ini = mid + 1 ; 
        }
        if(best) ans = max(ans, min(p_x[i] - (double)best - (double)i, p_y[best] - (double)i - (double)best)) ; 
    }
 
    cout << fixed << setprecision(4) << ans << "\n" ; 
 
}

• Subtask 1: 20 / 20
• Subtask 2: 40 / 40
• Subtask 3: 40 / 40