1. 打印出所有的"水仙花数",所谓"水仙花数"是指一个三位数,其各位数字立方和等于该数本身。例如:153是一个"水仙花数",因为153=1的三次方+5的三次方+3的三次方。(知识点:循环语句、条件语句)
package chap1; public class Main { public static void main(String[] args) { for (int i = 100; i < 1000; i++) { int bai = i / 100; int shi = i / 10 % 10; int ge = i % 10; if (Math.pow(bai, 3) + Math.pow(shi, 3) + Math.pow(ge, 3) == i) { System.out.println(i); } } } }
2.在控制台输出以下图形(知识点:循环语句、条件语句)
package chap1; public class Main { public static void main(String[] args) { for (int i = 0; i < 6; i++) { for (int j = 1; j <= i + 1; j++) { System.out.print(j); } System.out.println(); } System.out.println(); for (int i = 6; i >= 1; i--) { for (int j = 1; j <= i; j++) { System.out.print(j); } System.out.println(); } System.out.println(); for (int i = 0; i < 6; i++) { for (int j = 5; j > i; j--) { System.out.print(" "); } for (int j = 1; j <= i + 1; j++) { System.out.print(j); } System.out.println(); } System.out.println(); for (int i = 0; i < 6; i++) { for (int j = 0; j < i; j++) { System.out.print(" "); } for (int j = 1; j <= 6 - i; j++) { System.out.print(j); } System.out.println(); } } }
3. 输入年月日,判断这是这一年中的第几天(知识点:循环语句、条件语句)
package chap1; import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner s = new Scanner(System.in); System.out.println("请依次输入年月日:"); int nian = s.nextInt(); int yue = s.nextInt(); int ri = s.nextInt(); int days = 0; switch (yue) { case 1: days = 0; break; case 2: days = 31; break; case 3: days = 59; break; case 4: days = 90; break; case 5: days = 120; break; case 6: days = 151; break; case 7: days = 181; break; case 8: days = 212; break; case 9: days = 243; break; case 10: days = 273; break; case 11: days = 304; break; case 12: days = 334; break; default: System.out.println("年份错误"); return; } if (nian % 4 == 0 && nian % 100 != 0 || nian % 400 == 0) { if (yue > 2) { days ++; } } System.out.println("这是" + nian + "年的第" + (days + ri) + "天"); } }
4.由控制台输入一个4位整数,求将该数反转以后的数,如原数为1234,反转后的数位4321(知识点:循环语句、条件语句)
package chap1; import java.util.Scanner; public class Main { public static void main(String[] args) { Scanner s = new Scanner(System.in); System.out.println("请输入一个四位数:"); int num = s.nextInt(); int ge = num % 10; int shi = num / 10 % 10; int bai = num / 100 % 10; int qian = num / 1000; System.out.println("反转后结果为:" + ge + shi + bai + qian); } }