sumofarray.java

一些java程序

package exercise_java;


public class SumOfArray {
	public static void main(String[] args){
		final int NUMBER=2009;
		int num1,num2,sum=0;
		int i=1;
		do{
			sum+=i;
			i++;
			
		}while(sum<=NUMBER);
		num1=sum;
		num2=sum-i;
		if(Math.abs(num1-NUMBER)<Math.abs(num2-NUMBER))
			System.out.println("the most approximate number is "
					+i+" the sum of 1+2+3+...is "+num1);
		else if ((Math.abs(num1-NUMBER)<Math.abs(num2-NUMBER)))
			System.out.println("the most approximate number is "
					+(i-1)+" the sum of 1+2+3+...is "+num2);
		else 
			System.out.println("the most approximate number is "
					+i+" or "+(i-1)+" the sum of 1+2+3+...is "+num1);
		
	}

}