Java基础04（题）

import java.util.Scanner;

public class Test5 {

	public static void main(String[] args) {
		//输入一个数打印1到这个数中间各个位数相加为5的数
		int res = 0;
		int count = 0;
		int c = 0;
		Scanner sc = new Scanner(System.in);
		int j = sc.nextInt();
		for (int i = 5; i <= j; i++) {

			for (int k = 1; k <= i;) {
				int l0 = i / k % 10;
				res += (l0 * k);
				count += l0;
				k *= 10;
			}

			if (count == 5) {
				c++;
				System.out.println(res);
			}
			count = 0;
			res = 0;
		}
		System.out.println("满足条件的共有" + c + "个");

	}
}

鸡兔同笼和百元百鸡问题

public class Test23 {
   
	public static void main(String[] args) {
		// 鸡兔同笼  i对应鸡数
//		int i = 0;
//		while (i <= 80) {
//			if (i * 2 + (80 - i) * 4 == 208) {
//				System.out.println("鸡有" + i + "只，兔有" + (80 - i) + "只");
//			}
//			i++;
//		}
     //百元百鸡
		for (int i = 0; i <= 20; i++) {
			for (int j = 0; j <= 33; j++) {
				if ((100 - i - j) % 3 == 0 && 5 * i + (100 - i - j) / 3 + 3 * j == 100) {
					System.out.println("鸡翁有" + i + "只，鸡母有" + j + "只，鸡雏有" + (100 - i - j) + "只");
				}
			}
		}

	}

}

打印100~205间的质数

public class Test2 {
	public static void main(String[] args) {
		int k;
		int i;
		int count = 0;
		for (k = 101; k <= 205; k++) {
			for (i = 2; i <= (int) Math.sqrt(k); i++) {
				if (k % i == 0) {
					break;
				}
			}
			if (i > (int) Math.sqrt(k)) {
				System.out.print(k + "t");
				count++;
				if (count != 0 && count % 6 == 0) {
					System.out.println();
				}

			}

		}
		System.out.println("n" + count + "个质数");
	}
}