无序数组a，求a[i]-a[j]的最大值，且i<j

一道面试题：对于无序数组a，求a[i]-a[j]的最大值，其中i<j

---

 

package test;

import java.util.Arrays;

public class FindMax {
    public static void main(String[] args) {
        int[] a = new int[] { 9, 20, 3, 16, 6, 5, 7, 1 };
        System.out.println("a[" + a.length + "]=" + Arrays.toString(a));
        System.out.println("find max of a[i]-a[j],i<j : " + findMax(a));
    }

    public static int findMax(int[] a) {
        // 初始化为最小可能的int值
        int max = Integer.MIN_VALUE;
        // a[i]右边元素中的最小值
        int minRight = a[a.length - 1];
        int tempMax;
        for (int i = a.length - 2; i >= 0; i--) {
            tempMax = a[i] - minRight;
            if (a[i] < minRight) {
                minRight = a[i];
            }
            if (tempMax > max) {
                max = tempMax;
            }
        }
        return max;
    }
}