function version → find the smallest prime number greater than the given number

[Algorithm code 1]
** Function version algorithm code ← Find the smallest prime number greater than a given number

#include <bits/stdc++.h>
using namespace std;
 
bool isPrime(int n) {
    if(n==1) return false;
    for(int i=2; i<=sqrt(n); i++) {
        if(n%i==0) return false;
    }
    return true;
}
 
int getPrime(int n) { //Get least prime bigger than n
    for(int i=n+1; ;i++) {
        if(isPrime(i)) {
            return i;
            break;
        }
    }
}
 
int main(){
    int n;
    cin>>n;
    cout<<getPrime(n)<<endl;
    return 0;
}
 
 
/*
in:100
out:101
*/

Find the code for the largest prime number smaller than a given number, see: https://blog.csdn.net/hnjzsyjyj/article/details/127699346


[Algorithm code 2]
** Non-function version algorithm code ← Find the smallest prime number larger than a given number

#include <bits/stdc++.h>
using namespace std;

int main(){
    int n;
    cin>>n;
    for(int i=n+1; ;i++){
        int flag=1;
        for(int j=2;j<=sqrt(i);j++){
            if(i%j==0){
                flag=0;
                break;
            }
        }
        if(flag==1){
            cout<<i<<endl;
            break;
        }
    }

    return 0;
}


/*
in:100
out:101

in:1000
out:1009
*/