Submission #796199

#	Time	Username	Problem	Language	Result	Execution time	Memory
796199		Sandarach151	Sure Bet (CEOI17_sure)	C++17	100 / 100	78 ms	5168 KiB

sure

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

int main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    int n;
    cin >> n;
    double arr1[n];
    double arr2[n];
    for(int i=0; i<n; i++){
        cin >> arr1[i] >> arr2[i];
    }
    sort(arr1, arr1+n, greater<double>());
    sort(arr2, arr2+n, greater<double>());
    double pref1[n];
    double pref2[n];
    pref1[0]=arr1[0]-1;
    pref2[0]=arr2[0]-1;
    for(int i=1; i<n; i++){
        pref1[i]=pref1[i-1]+arr1[i]-1;
        pref2[i]=pref2[i-1]+arr2[i]-1;
    }
    double maxx = 0;
    for(int i=0; i<n; i++){
        if(pref1[i]<=0){
            break;
        }
        else{
            // find first position such that pref1[i]-b<pref2[b]-i
            int pos1 = 0;
            int pos2 = n-1;
            while(pos1<pos2){
                int mid = (pos1+pos2)/2;
                if(pref1[i]-mid<=pref2[mid]-i){
                    pos2 = mid;
                }
                else{
                    pos1=mid+1;
                }
            }
            maxx = max(maxx, min(pref1[i]-pos1, pref2[pos1]-i)-1);
            if(pos1>0){
                maxx = max(maxx, min(pref1[i]-(pos1-1), pref2[pos1-1]-i)-1);
            }
            if(pos1<n-1){
                maxx = max(maxx, min(pref1[i]-(pos1+1), pref2[pos1+1]-i)-1);
            }
        }
    }
    printf("%.4lf",(double) maxx);
    return 0;
}

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