无聊打开了自己很久以前下的《微软、谷歌、百度等公司经典面试 100 题》的PDF文件。
1、有一个整数数组,请求出两两之差绝对值最小的值,
记住,只要得出最小值即可,不需要求出是哪两个数。
解法思路：

1. 将数组排序。
2. 遍历数组，找出数组相邻值之差绝对值最小的数值。
   Java代码：

import java.util.Arrays;

public class Solution{

    public int minSub(Integer[] array){
        Arrays.sort(array);
        int minSub = Integer.MAX_VALUE;
        int sub = Integer.MAX_VALUE;
        for(int i = 0;i < array.length - 1;i ++){
                sub = Math.abs(array[i + 1] - array[i]);
                minSub = (sub < minSub) ? sub : minSub;
        }

        return minSub;
    }
}

测试

import java.util.Arrays;
import java.util.Collection;

import org.junit.Test;
import org.junit.Before;
import org.junit.runners.Parameterized;
import org.junit.runners.Parameterized.Parameters;
import org.junit.runner.RunWith;
import static org.junit.Assert.assertEquals;

import org.junit.runner.JUnitCore;
import org.junit.runner.Result;
import org.junit.runner.notification.Failure;

@RunWith(Parameterized.class)
public class Test1{
    private Integer[] testArray = null;
    private Integer testMinSub = Integer.MAX_VALUE;

    private Solution solution = null;
    
    @Before
    public void initialize(){
        solution = new Solution();
    }
    
    @Parameterized.Parameters
    public static Collection testData(){
        return Arrays.asList(new Object[][]{
            {new Integer[]{23, 3, 4, 6, 9, 154}, 1},
            {new Integer[]{23, 21, 28, 76, 39, 154}, 2},
            {new Integer[]{23, 5, 10, 43}, 5}
        });
    }

    @Test
    public void testMinSub(){
        System.out.println("test_input: " + testArray.toString());
        assertEquals((long) testMinSub, (long)solution.minSub(testArray));
    }

    public Test1(Integer[] array, Integer testMinSub){
        this.testArray = array;
        this.testMinSub = testMinSub;
    }
    
    public static void main(String[] args){
        Result result = JUnitCore.runClasses(Test1.class);
        for(Failure failure:result.getFailures()){
            System.out.println(failure.toString());
        }

        System.out.println(result.wasSuccessful());
    }
}