4.2上机练习

public class two {

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        
        int a,b,c;
        for(int i=100;i<1000;i++){
            a=i/100;
            b=i%100/10;
            c=i%10;
            if(a*a*a+b*b*b+c*c*c==i){
                System.out.println(i);
            }
        }
        
        
    }

}

import java.util.*;
public class two 
{
    public static void main(String[] args) {
        for(int i=1;i<=7;i++) {
            for(int j=1;j<i;j++) {
                System.out.print(j);
            }
            System.out.println();
        }
    }
}

import java.util.*;
public class two 
{
    public static void main(String[] args) {
        for(int i=6;i>=0;i--) {
            for(int j=1;j<=i;j++) {
                System.out.print(j);
            }
            System.out.println();
        }
    }
}

import java.util.*;
public class two 
{
    public static void main(String[] args) {
        for(int i=1;i<7;i++) {
            for(int j=i;j>0;j--) {
                System.out.print(j);
            }
            System.out.println();
        }
    }
}

import java.util.*;
public class two 
{
    public static void main(String[] args) {
        for(int i=6;i>0;i--) {
            for(int k=0;k<6-i;k++) {
                System.out.print(" ");
            }
            for(int j=1;j<=i;j++) {
                System.out.print(j);
            }
            System.out.println("");
        }
    }
}

import java.util.*;
public class two 
{
    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);
        int day=0;
        int month=0;
        int year=0;
        int sum=0;
        int leap;
        System.out.print("请输入年-月-日\n");
        Scanner sc = new Scanner(System.in);
        year=input.nextInt();
        month=input.nextInt();
        day=input.nextInt();
        switch(month) /*先计算某月以前月份的总天数*/
        {
        case 1:
          sum=0;break;
        case 2:
          sum=31;break;
        case 3:
          sum=59;break;
        case 4:
          sum=90;break;
        case 5:
          sum=120;break;
        case 6:
          sum=151;break;
        case 7:
          sum=181;break;
        case 8:
          sum=212;break;
        case 9:
          sum=243;break;
        case 10:
          sum=273;break;
        case 11:
          sum=304;break;
        case 12:
          sum=334;break;
        default:
          System.out.println("data error");break;
        }
        sum=sum+day; /*再加上某天的天数*/
        if(year%400==0||(year%4==0&&year%100!=0))/*判断是不是闰年*/
          leap=1;
        else
          leap=0;
        if(leap==1 && month>2)/*如果是闰年且月份大于2,总天数应该加一天*/
          sum++;
        System.out.println("这天在这年的天数为:"+sum);

    }
}

import java.util.*;
public class two 
{
    public static void main(String[] args) {
        System.out.print("请输入数字\n");
        Scanner sc = new Scanner(System.in);
        int x = sc.nextInt();
           if(x>999 && x<=9999){
               int gewei = x%10;
               int shiwei = x % 100 / 10;
               int baiwei = x%1000/100;
               int qianwei = x/1000;
               int sum = qianwei + baiwei*10 +shiwei*100 +gewei*1000;
               System.out.println(sum);
           }
           else{
               System.out.println("error");
           }

    }
}