2020년 10월 13일 숙제

package com.kh.control.loop.practice;

import java.util.Scanner;

public class LoopPractice {---

	public void practice1() {
		Scanner sc = new Scanner(System.in);
		System.out.print("1 이상의 숫자를 입력하세요 : ");
		int input = sc.nextInt();
		
		if(input >= 1) {
			for(int i = 1; i <= input; i++) {
				System.out.print(i + " ");
			}
		} else {
			System.out.println("1 이상의 숫자를 입력해주세요.");
		}
	}
	
	public void practice2() {
		Scanner sc = new Scanner(System.in);
		System.out.print("1 이상의 숫자를 입력하세요 : ");
		int input = sc.nextInt();
		
		if(input >= 1) {
			for(int i = input; i >= 1; i--) {
				System.out.print(i + " ");
			}
		} else {
			System.out.println("1 이상의 숫자를 입력해주세요.");
		}
	}
	
	
	public void practice3() {
		Scanner sc = new Scanner(System.in);
		System.out.print("정수를 하나 입력하세요 : ");
		int input = sc.nextInt();
		
		int sum = 0;
		for(int i = 1; i <= input; i++) {
			if (i != input) {
			System.out.print(i + " + ");
			} else {
				System.out.print(i + " = ");
			}
			sum += i;
		}
		System.out.println(sum);
	}
	
	public void practice4() {
		Scanner sc = new Scanner(System.in);
		System.out.print("첫 번째 숫자 : ");
		int num1 = sc.nextInt();
		System.out.print("두 번째 숫자 : ");
		int num2 = sc.nextInt();
		
		int temp = 0;
		if(num1 <= 0 || num2 <= 0) {
			System.out.println("1 이상의 숫자를 입력해주세요."); return;
		} else if(num1 > num2) {
			temp = num1;
			num1 = num2;
			num2 = temp;
		} 
		
		for(int i = num1; i <= num2; i++) {
			System.out.print(i + " ");
		}
	}
	
	
	public void practice5() {
		Scanner sc = new Scanner(System.in);
		System.out.print("숫자 : ");
		int num = sc.nextInt();
		System.out.println("==== " + num + "단  ====");
		for(int i = 1; i <= 9; i++) {
			System.out.printf("%d * %d = %d\n", num, i, num*i);
		}
	}
	
	public void practice6() {
		Scanner sc = new Scanner(System.in);
		System.out.print("숫자 : ");
		int num = sc.nextInt();
		if (num < 10) {
			for (int i = num; i <= 9; i++) {
				System.out.println("==== " + i + "단  ====");
				for (int j = 1; j <= 9; j++) {
					System.out.printf("%d * %d = %d\n", i, j, num * j);
				} System.out.println();
			}
		} else {
			System.out.println("9 이하의 숫자만 입력해주세요.");
		}
	}
	
	public void practice7() {
		Scanner sc = new Scanner(System.in);
		System.out.print("정수 입력 : ");
		int num = sc.nextInt();
		
		for(int row = 1; row <= num; row++) {
			for(int col = 1; col <= row; col++) {
				System.out.print("*");
			} 
			System.out.println();
		}
	}
	
	public void practice8() {
		Scanner sc = new Scanner(System.in);
		System.out.print("정수 입력 : ");
		int num = sc.nextInt();
		
		int count = num;
		for(int row = num; row >= 1; row--) {
			for(int col = row; col >= 1; col--) {
				System.out.print("*");
			} 
			System.out.println();
		}
	}
	
	public void practice9() {
		Scanner sc = new Scanner(System.in);
		System.out.print("자연수 하나를 입력하세요 : ");
		int num = sc.nextInt();
		
		int count = 0;
		for(int i = 2; i <= num; i++) {
			if(i % 2 == 0 || i % 3 == 0) {
				System.out.print(i + " ");
				if(i % 2 == 0 && i % 3 == 0) {
					count++;
				}
			}
		}
		
		System.out.print("\ncount : " +  count);
		
	}
	
	
	public void practice10() {
		Scanner sc = new Scanner(System.in);
		System.out.print("정수 입력 : ");
		int num = sc.nextInt();

		for (int i = 1; i <= num; i++) {
			for (int j = num - i; j > 0; j--) {
				System.out.print(" ");
			}
			for (int k = 1; k <= i; k++) {
				System.out.print("*");
			}
			System.out.println();
		}
	}
	
	public void practice11() {
		Scanner sc = new Scanner(System.in);
		System.out.print("정수 입력 : ");
		int input = sc.nextInt();
		int num = input * 2 - 1;

		int count = 1;
		for (int i = 1; i <= num; i++) {
			if (i <= input) {
				for (int j = 1; j <= i; j++) {
					System.out.print("*");
				}
				System.out.println();
			} else {
				for (int k = input - count; k >= 1; k--) {
					System.out.print("*");
				}
				count++;
				System.out.println();
			}
		}
	}
	
	
	public void practice12() {
		Scanner sc = new Scanner(System.in);
		System.out.print("정수 입력 : ");
		int input = sc.nextInt();
		
		int star = input * 2 - 1;
		
		for(int i = 1; i <= input; i++) {
			for(int j = input - i; j > 0; j--) {
				System.out.print(" ");
				
			}
			for(int k = 1; k <= star; k+=2) {
				System.out.print("*");
			}
			
			System.out.println();
		}
		
	}

	}