Hello all, I am trying to find the complexity of the below code
"#include <bits/stdc++.h>
using namespace std;
int main() {
long long int n;
cin>>n;
vector<int>factors[1000001];
for(int i=2;i<=n;i++)
{
for(int j=1;j*i<=n;j++)
{
factors[j*i].push_back(i);
}
}
return 0;
}"
What I am mainly doing in the code is trying to store factors of all the numbers from 1 to n (n<=1000000). As you can see , factors is a vector of vectors. factors[i] will store all the factors for number i. The code works as follows 1. Fix a number i in the outer loop 2. For all the multiples of i that lies within n, push i as it's factor-->this is being done in the inner loop. According to my calculation, the complexity should be nlog(n) which should easily pass in a time limit of 1s but when I am running the above code on Codechef compiler with n=1000000, the execution time is coming >2s.
If anyone can kindly help, I will be highly obliged. Thank you..