Submission #321873

#	Time	Username	Problem	Language	Result	Execution time	Memory
321873		Karen124	Sure Bet (CEOI17_sure)	C++14	100 / 100	218 ms	5356 KiB

sure

#pragma GCC optimize("O2")
#pragma GCC optimize("unroll-loops")
#include <bits/stdc++.h>
     
using namespace std;
     
#define ll long long int 
#define F first
#define S second
#define pb push_back
 
const ll N = 1e5 + 10;
const ll LOG = 20;
const ll MOD = 1e9 + 7;
const ll INF = 1e9 + 10;
int n;
long double a[N], b[N], ans = 0;
long double f(int i, int j){
    return min(a[i] - (long double)j, b[j] - (long double)i);
}
int main() {
    cin >> n;
    for (int i = 1; i <= n; i++){
        cin >> a[i] >> b[i];
        a[i] --; b[i] --;
    }
    sort(a + 1, a + n + 1); reverse(a + 1, a + n + 1);
    sort(b + 1, b + n + 1); reverse(b + 1, b + n + 1); 
    for (int i = 1; i <= n; i++){
        a[i] += a[i - 1];
        b[i] += b[i - 1];
    }
    for (int i = 0; i <= n; i++){
        int l = 0, r = n;
        while (l + 1 <= r){
            int mid = (l + r) / 2;
            if (f(i, mid) < f(i, mid + 1)) l = mid + 1;
            else r = mid;
        }
        ans = max(ans, f(i, r));
    }
    cout << fixed << setprecision(4) << ans << '\n';
    return 0;
}

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