Java小程序3（2015-8-10）

使用while单循环求1！+2！+3！+...+6!+7!

1、

public class Test33{  public static void main(String[]args){  

        int i=1;

        int j=1;  

        int sum=0;

        while (i<=7)         {     

                                j=j*i;                

                                i++;   

                             sum=sum+j;//1*1+1*1*2+1*1*2*3....

         }  System.out.println(sum);  } }

2、

public class Test3{

             public static void main(String[] args){        

                           int i = 1;  

                           int j = 1;  

                           int sum = 0;   

                                    //--每个数阶乘的和  

                          int jc = 1;

                 /*   sum = 1*1+1*2+1*2*3+1*2*3*4......   */

              while(i<=7){       

                                 //--单独的每个数的阶乘和    

                            while(j<=i){         

                                       jc = jc*j;    

                                            j++;    

                            }    

                            i++;       

                              sum = sum + jc;    

  }   System.out.println("sum:"+sum);

 } }