Deepak and Primes

#1

2 testcases are failing .Here’s the code:

#2

The 5,000,000th prime is 86,028,121.

so atleast this much space you require

as size of array is long and you need to save only 1 or 0
so rather than int use bool arr[100000001]={};
do some more optimzations like
iterate only odd nos as all prime are odd except 2

you can take help from this

// PrimeSeive.cpp

#include<iostream>
#include<vector>
using namespace std;
#define ll long long int
bool prime [100000005]={};
vector<int> Prime;
int main(){
	prime[0]=prime[1]=true;
	Prime.push_back(2);
	for(ll i=3;i<100000001;i+=2){
		
		if(!prime[i]){
			Prime.push_back(i);
			for(ll j=i*i;j<100000001;j+=i){prime[j]=true;}
		}
	}
	int n;cin>>n;
    cout<<Prime[n-1]<<endl;
	return 0;
}
#3

if i increase size of n or prime array then it gives error segmentation fault

#4

Have you make bool array?
And do optimization?

Send me link or code
I will see

#5

yes i did change the data type of array and now i am iterating to odd nos. only but still one test case is failing…i think its may be bcoz 1<=n<=5000000 n we are storing prime nos. till 1000000…how to find rest of the prime nos.

#6

here’s the link of updated code : https://ide.codingblocks.com/s/239652

#7

make arrays of size 10^8

and make global array

after that your code is giving correct ans

#8

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