Find the number of ways to partition array into segments such that sum of each segments is greater than 0,

Note- Concatenating the segments should result into full array.

Constraints: 1<=N<=10^5 1<=a[I]<=10^9 Example:

Input1: N=3, a[]={-1,-3,7}

Output: 1. (Complete array as one Segment)

Thanks

PS. This is not part of any running Contest.

This code is taking around 1300 ms. (size of set shouldn't exceed more than 1 at any time, Since I am inserting same element every time)

#include<bits//stdc++.h>
using namespace std;
int main()
{   
    set<int>s;
   for(int i=1;i<=7000001;i++)
   {    
        s.insert(1);
        s.erase(1);
   }
   
}

But , After commenting the s.erase(), it just took 15 ms.

#include<bits//stdc++.h>
using namespace std;
int main()
{   
    set<int>s;
   for(int i=1;i<=7000001;i++)
   {    
        s.insert(1);
       // s.erase(1);
   }
   
}

Can anyone please explain the reason behind this? Thanks in advance :)