二分法（有序 不重复）

package com.atsico.pkg0819;

import org.junit.Test;

import java.util.Arrays;

public class MainDemo {

public int selectBy2(int selectKey, int... iArr) {
    if (iArr == null) {
        return -1;
    }
    int start = 0;//数组最小索引值
    int end = iArr.length - 1;//数组最大索引值
    if (start > end) {
        return -1;
    }
    if (start == end) {
        if (selectKey == iArr[end]) {
            return start;
        }
        return -1;
    }
    while (start < end) {
        int middle = (start + end) / 2;//获取中间索引
        if (selectKey < iArr[middle]) {
            end = middle - 1;
        } else if (selectKey > iArr[middle]) {
            start = middle + 1;
        } else {
            return middle;
        }
    }
    return -1;
}

@Test
public void test_01() {
    int[] iArr = new int[]{2, 14, 19, 10, 243, 148, 199, 357};
    iArr = sortMethod(iArr);
    int i = selectBy2(243, iArr);
    System.out.println("key: 243 => value:" + i);
}

public int[] sortMethod(int... param) {
    int tempVal = 0;
    int[] iArr = param;
    for (int i = 0; i < iArr.length; i++) {
        for (int j = i + 1; j < iArr.length; j++) {
            if (iArr[i] > iArr[j]) {
                tempVal = iArr[j];
                iArr[j] = iArr[i];
                iArr[i] = tempVal;
                tempVal = 0;
            }
        }
    }
    System.out.println("冒泡排序：");
    for (int mem : iArr) {
        System.out.print(mem + " ");
    }
    return param;
}

}