goorm 약수의 합, 모양찍기, 소수 판별

#include <iostream>
using namespace std;
int main(void) {
		
	int n;
	cin >> n;
	int sum = 0;
	for(int i = 1; i <= n; i++){
		if(n%i==0){
			sum+=i;
		}
	}
	cout << sum;
	return 0;
}

 

#include <iostream>
using namespace std;
int main(void) {
	int n;
	cin >> n;
	for(int i = n; i > 0; i--){
		for(int j = 1; j<= i; j++){
			cout << "*";
		}
		cout <<endl;
	}
	return 0;
}

 

#include <iostream>
using namespace std;
int main(void) {
	
	int n;
	cin >> n;
	int sum = 0;
	for(int i = 2; i <n; i++){
		if(n%i==0){
			sum++;
		}
	}
	
	if(sum==0){
		cout << "True"<<endl;
	}
	else
		cout << "False"<<endl;
	
	return 0;
}