练习一：

package com.shhfg.ds;public class HelloWorld01 {public static void main(String[] args) {//个位7 十位7 7的倍数（逢7过）//100.fori//变量.forifor (int i = 0; i < 100; i++) {if (i%10==7 || i/10%10==7 || i%7==0){System.out.println("过");continue;}System.out.println(i);}}}

练习二：

package com.shhfg.ds;import java.util.Scanner;public class HelloWorld02 {public static void main(String[] args) {Scanner sc=new Scanner(System.in);//求平方根System.out.println("请输入一个整数");int number=sc.nextInt();for (int i = 1; i < number; i++) {if ( i * i ==number){System.out.println(i+"就是"+number+"的平方根");break;}else  if (i*i>number){System.out.println((i-1)+"就是"+number+"平方根的整数部分");break;}}}
}