[C++][BOJ/백준][단계별로 풀어보기] 3. for문

1. (2739번) 구구단

#include <iostream>

using namespace std;

int main()
{
	int N;
	
	cin >> N;
	
	for(int i=1; i<10 ;i++){
	cout << N << " * " << i <<" = "<< N*i<<endl;	
	}
	 
	
	return 0;
	
}

---

2. (10950번) A+B -3

#include <iostream>

using namespace std;

int main()
{
	int A, B, T;
	
	cin >> T;
	
	for(int i = 0; i < T; i++){
		cin >> A >> B;
		
		cout << A+B << endl;
	}
	
	return 0;
	
}

---

3. (8393번) 합

#include <iostream>

using namespace std;

int main()
{
	int n;
	int result = 0;
	
	cin >> n;
	
	for(int i = 0; i <= n ; i++){
		
		result += i;
	}
	
	cout << result;
	return 0;
	
}

---

5. (2741번) N찍기

#include <iostream>

using namespace std;

int main()
{
	int N;
	cin >> N;
	
	for(int i=1; i<=N; i++){
		cout << i <<'\n';
	}
	
	return 0;
	
}

---

6. (2742번) 기찍 N

#include <iostream>

using namespace std;

int main()
{
	int N;
	cin >> N;
	
	for(int i=0; i < N; i++){
		cout << N-i <<'\n';
		
	}
	
	return 0;
	
}

---

7.  (11021번) A+B - 7

#include <iostream>

using namespace std;

int main()
{
	int T;
	int A, B;
	cin >> T;
	
	for(int i = 1; i <=T; i++){
		
		cin >> A >> B;
		
		cout << "Case #" << i << ": " << A+B << endl;
	}
	
	return 0;
	
}

---

8. (11022번) A+B - 8

#include <iostream>

using namespace std;

int main()
{
	int T;
	int A, B;

	cin >> T;
	
	for(int i=1; i <= T; i++){
	cin >> A >> B;
	cout << "Case #" << i << ": " << A << " + " << B << " = " << A+B << endl;		
		
	}
}

---

9. (2438번) 별 찍기 - 1

#include <iostream>

using namespace std;

int main()
{
	int N;
	cin >> N;
	
	for(int i=1; i<=N ; i++){
		
		for(int j=1; j<=i; j++){
			
			cout << "*";
		}
		
		cout<<endl;
		
	}
	
	return 0;
}

---

10. (2439번) 별 찍기 - 2

#include <iostream>

using namespace std;

int main()
{
	int N;
	cin >> N;
	
	int space = 0;
	
	for(int i=1; i<=N; i++){
		
		for(int j = 1; j<=N-i; j++){
			
			cout << " ";
			
		}
		
		for(int k = 1; k<=i; k++){
				
				cout << "*";
			}
			
		cout << endl;

	}

}

---

11. (10871번) X보다 작은 수

#include <iostream>

using namespace std;

int main()
{
	int N, X;
	cin >> N >> X;
	int A;
	
	for(int i = 1; i<=N; i++){
		cin >> A;
		
		if(A<X)
		cout << A << endl;
	}

}