Submission #761613

#	Time	Username	Problem	Language	Result	Execution time	Memory
761613		gggkik	도넛 (JOI14_ho_t3)	C++14	100 / 100	247 ms	7508 KiB

2014_ho_t3

#include <bits/stdc++.h>
using namespace std;
const int MXN = 1e5+5;
#define ll long long
ll A[MXN], P[MXN], n, all;
vector<ll> sa, sb;
ll cut(ll x,int i){
    return all-
        *lower_bound(sa.begin(),sa.end(),x+P[i])-
        *lower_bound(sb.begin(),sb.end(),x-P[i]);
}
int f(ll x){ // 답이 x 이상인가?
    for(int i = 0;i<n;i++) // i에서 cut
        if(cut(x,i)>=x) return 1;
    return 0;
}
ll sum(int i,int j){return (i<=j?P[j]-P[i-1]:0);}
int main() {
    cin.tie(0)->sync_with_stdio(0);
    cin >> n;
    for(int i = 1;i<=n;i++){
        cin >> A[i]; P[i] = P[i-1]+A[i];
    }
    all = P[n];
    ll suma = 0, sumb = 0;
    sa.push_back(0);
    for(int t = 0;t<2;t++)
        for(int i = 1;i<=n;i++){
            suma += A[i]; sa.push_back(suma);
        }
    for(int i = n;i>0;i--){
        sumb += A[i]; sb.push_back(sumb);
    }
    for(int i = 0;i<=n;i++) sb.push_back(-P[i]);
    sort(sb.begin(),sb.end());
    ll l = 0, r = all;
    for(;l+1<r;){
        ll mid = l+r>>1;
        if(f(mid)) l = mid;
        else r = mid;
    }
    cout << l;
}

Compilation message (stderr)

2014_ho_t3.cpp: In function 'int main()':
2014_ho_t3.cpp:38:19: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   38 |         ll mid = l+r>>1;
      |                  ~^~

• Subtask 1: 5 / 5
• Subtask 2: 15 / 15
• Subtask 3: 30 / 30
• Subtask 4: 50 / 50