Submission #146473

#	Time	Username	Problem	Language	Result	Execution time	Memory
146473		achibasadzishvili	Bigger segments (IZhO19_segments)	C++14	100 / 100	178 ms	44372 KiB

segments

#include<bits/stdc++.h>
#define ll long long
#define f first
#define s second
#define pb push_back
using namespace std;
ll n,a[500005],s[500005],ans[500005],ind;
vector<pair<ll,ll> >v[500005];
int main(){
    ios::sync_with_stdio(false);
    cin >> n;
    
    for(int i=1; i<=n; i++){
        cin >> a[i];
        s[i] = s[i - 1] + a[i];
    }
    pair<ll,ll> p = make_pair(0 , 0);
    for(int i=1; i<=n; i++){
        for(int j=0; j<v[i].size(); j++)
            if(v[i][j].f > p.f)
                p = v[i][j];
            else if(v[i][j].f == p.f)
                    p = max(p , v[i][j]);
        ind = p.s;
        ans[i] = ans[ind] + 1;
        pair<ll,ll> ne = make_pair(ans[i] , i);
        ll l = i + 1,r = n,mid,ik = -1;
        while(r >= l){
            mid = (l + r) / 2;
            if(s[mid] - s[i] >= s[i] - s[ind]){
                r = mid - 1;
                ik = mid;
            }
            else {
                l = mid + 1;
            }
        }
        if(ik != -1){
            v[ik].pb(ne);
        }
    }
    
    
    cout << ans[n] << endl;
    
    
    
    
    return 0;
}

Compilation message (stderr)

segments.cpp: In function 'int main()':
segments.cpp:19:23: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
         for(int j=0; j<v[i].size(); j++)
                      ~^~~~~~~~~~~~

• Subtask 1: 13 / 13
• Subtask 2: 14 / 14
• Subtask 3: 10 / 10
• Subtask 4: 36 / 36
• Subtask 5: 27 / 27