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)
int a,b,c,i; for(i=100;i<1000;i++){ a=i/100; b=i/10%10; c=i%10; if(a*a*a+b*b*b+c*c*c==i){ System.out.println(i); } } } }
2.
for(int i=1;i<=6;i++){ for (int j=1;j<=i;j++){ System.out.print(j); } System.out.println(); } int a = 6; for (int i = 0; i <= a; i++) { System.out.println(); for (int j = 1; j <= a - i; j++) { System.out.print(j); } } for (int i = 0; i <= a; i++) { for (int j = 1; j <= a - 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)
int year; int mouth; int day = 0; int days; int d = 0; // 累计天数 int e = 0; Scanner scanner = new Scanner(System.in); //判断输入的年份和月份和日期是否错误 do { System.out.println("输入年:"); year = scanner.nextInt(); System.out.println("输入月:"); mouth = scanner.nextInt(); System.out.println("输入日:"); days = scanner.nextInt(); if (year < 0 || mouth < 0 || mouth > 12 || days < 0 || days > 31) { System.out.println("input error!"); e = 1; } } while (e == 1); for (int i = 1; i < mouth; i++) { switch (i) { case 1: case 3: case 5: case 7: case 8: case 10: case 12: { day = 31; break; } case 4: case 6: case 9: case 11: { day = 30; break; } case 2: { if ((year % 100 != 0 && year % 4 == 0) || (year % 100 == 0 && year % 400 == 0)) { day = 29; } else { day = 28; } } default: break; } d += day; } System.out.println("这是" + year + "年的" + (d + days) + "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)
int i = sc.nextInt(); if(i>999 && i<10000){ int a = i%10; int b = i % 100 / 10; int c = i%1000/100; int d = i/1000; int sum = d + c*10 +b*100 +a*1000; System.out.println("反转数为"+sum); } else{ System.out.println("error"); }
在控制台输出以下图形