kindly help me out to optimise my code.
#include<bits/stdc++.h>
using namespace std;
int main() {
int t; cin>>t;
long long int n;
while(t--)
{
cin>>n;
int res=0;
for(int i=2;i<=n;i++)
{
if(i%2==0 || i%3==0 || i%5==0 || i%7==0 || i%9==0 || i%11==0 || i%13==0 || i%15==0 || i%17==0 || i%19==0)
{
res++;
}
}
cout<<res<<endl;
}
return 0;
}
Hello @raj_pareek
This question is based on inclusion exclusion principle (Set theory)
let a,b,c,d,e,f… represent set of prime numbers less than 20.
Now you have to find
a union b union c union d…
this can be found by inclusion exclusion principle.
In case you need explanation do post it.
got it, i will try and get back to you asap if get any issue,thanks!!
@raj_pareek yes you should try and incase you are unable to think then you can see this video of prateek sir:
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