Prime Visits Problem

#1

1 out of 3 test cases is showing Run error.

#include<iostream>
#define ll long long int
using namespace std;

int prime_visits(int sieve[], int a, int b){
	for(int i=3; i<=b; i+=2){
		sieve[i] = 1;
	}

	for(int i=3; i<=b; i+=2){
		if(sieve[i] == 1){
			for(ll j=i*i; j<=b; j+=i){
				sieve[j] = 0;
			}
		}
	}
	
	sieve[2] = 1;

	int cnt = 0;
	for(int i=a; i<=b; i++){
		if(sieve[i] == 1){
			cnt++;
		}
	}
	return cnt;
}


int main() {

	int t;
	cin>>t;
	while(t--){
		int a,b;
        cin>>a>>b;
		int sieve[1000005]{0};
		cout<<prime_visits(sieve,a,b)<<endl;

	}

	return 0;
}
#2

i think you passed all testcase now

any further doubt

#3

No.
For the code that i’ve shared, one test case is failing.

#4

Make i as long long int also

Modified Code

#5

yes all test cases passed now

But why do we need to declare i as long long int?
In the loop, i<=b, and b<=10^6, so why we needed to do that?

#6

because ii will be integer if i is integer
so make i ll so that ii will also be ll and don’t overflow

#7

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