Submission #1027224

#	Time	Username	Problem	Language	Result	Execution time	Memory
1027224		vjudge1	Sure Bet (CEOI17_sure)	C++17	100 / 100	53 ms	1996 KiB

sure

#include<bits/stdc++.h>
#define int long long
#define fi first
#define se second
#define pb push_back
#define ii pair<int, int>
#define sz(v) (int)v.size()
#define all(v) v.begin(), v.end()
using namespace std;

const int N=1e5+5, mod = 1e9+7, inf = 1e18;

int n;
double a[N], b[N];

signed main() {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    cin >> n;
    for (int i=1; i<=n; i++) {
        cin >> a[i] >> b[i]; a[i]-=1.0; b[i]-=1.0;
    }

    sort(a+1, a+n+1, greater<double>()); sort(b+1, b+n+1, greater<double>());
    for (int i=1; i<=n; i++) {
        a[i] += a[i-1]; b[i] += b[i-1];
    }

    double res = (double) -inf;
    for (int na = 0; na<=n; na++) {
        int lo = 0, hi = n, ans = -1;
        while(lo<=hi) {
            int mid = (lo+hi)>>1;
            if(a[na] - mid >= b[mid] - na) {
                ans = mid;
                lo = mid+1;
            } else {
                hi = mid-1;
            }
        }
        if(ans != -1) res = max(res, b[ans]-na);
        if(ans<n) res = max(res, a[na]-ans-1);
    }
    cout << fixed << setprecision(4) << res;
}

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