Submission #769914

#	Time	Username	Problem	Language	Result	Execution time	Memory
769914		Ahmed57	Bigger segments (IZhO19_segments)	C++17	100 / 100	60 ms	18480 KiB

segments

#pragma GCC optimize("Ofast")
#include <bits/stdc++.h>

using namespace std;
int main(){
    ios_base::sync_with_stdio(false);cin.tie(0);cout.tie(0);
    long long n;cin>>n;
    long long arr[n];
    vector<long long> pref = {0};
    for(int i = 0;i<n;i++){
        cin>>arr[i];
        pref.push_back(pref.back()+arr[i]);
    }
    vector<pair<long long,int>> v;v.push_back({0,0});
    int dp[n+1] = {0};
    int it = 0;
    for(int i = 1;i<=n;i++){
        if(v[it].first>pref[i])it--;
        while(it+1<v.size()&&v[it+1].first<=pref[i])it++;
        dp[i] = dp[v[it].second]+1;
        long long sum = pref[i]+pref[i]-pref[v[it].second];
        while(!v.empty()&&v.back().first>=sum)v.pop_back();
        v.push_back({sum,i});
    }
    cout<<dp[n]<<endl;
    return 0;
}

Compilation message (stderr)

segments.cpp: In function 'int main()':
segments.cpp:19:19: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<std::pair<long long int, int> >::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   19 |         while(it+1<v.size()&&v[it+1].first<=pref[i])it++;
      |               ~~~~^~~~~~~~~

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