binarysearch.java

关于数组的一些算法

import com.kettas.common.*;
public class BinarySearch{
	public static void main(String args[]){
		int[] a = {1, 2, 3, 5, 9};
		int begin = 0;
		int end = a.length - 1;
		int mid = (begin + end) / 2;
		
		int n = SystemIn.readInt();
		
		while(mid != begin){
			if(a[mid] == n) break;
			
			if (a[mid] > n) end = mid;
			if (a[mid] < n) begin = mid;
			
			mid = (begin + end) / 2;
		}
		
		if (a[mid] == n){
			System.out.println("Found " + n + " at Index "+ mid);
		}else if(a[end] == n){
			System.out.println("Found " + n + " at Index "+ end);
		}else{
			System.out.println("Not Found");
		}
		
	}
}