hw5_23.java

JAVA 2面向对象程序设计(习题参考答案1-8).rar

public class hw5_23
{
   public static void main (String args[])
   {
      int num,num1=0;
      int sum=0,sum1=0;
      System.out.println("计算1^2-2^2+3^2-4^2+...-50^2");
      for (num=1;num<=50;num++)
      {
         num1=num*num;
         if ((num%2)==1) 
            sum+=num1;
         if ((num%2)==0)
            sum1+=num1;
      }
      System.out.println("其总和为"+(sum-sum1));
   }
}