Binary Search Algorithm All In One

二分搜索算法

https://www.geeksforgeeks.org/complexity-analysis-of-binary-search/

"use strict";

/**
 *
 * @author xgqfrms
 * @license MIT
 * @copyright xgqfrms
 * @created 2019-08-22
 *
 * @description binary search
 * @augments
 * @example
 * @link
 *
 */

let log = console.log;

// 2.写一个函数，对于一个排好序的数组，如果当中有两个数的和为某个给定的数target，返回true，否则false，时间复杂度O(n)

// supplement
const binarySearch = (arr = [], target, debug = false) => {
    let result = false;
    let temp = [];
    for (let i = 0; i < arr.length; i++) {
        let supplement = ``;
        supplement = target > arr[i] ? target - arr[i] : arr[i] - target;
        if (debug) {
            log(`supplement =`, supplement);
        }
        if (arr.includes(supplement)) {
            if (!temp.includes(supplement)) {
                temp.push(supplement);
            }
        }
    }
    if (temp.length >= 2) {
        result = true;
    }
    if (debug) {
        log(`temp =`, temp);
    }
    return result;
};


log(binarySearch([1,3,5,7,9], 9));
// false
log(binarySearch([1,3,5,7,9], 4));
// true
log(binarySearch([-1,3,5,7,9], 4));
// true

167. 两数之和 II - 输入有序数组

https://leetcode.com/problems/two-sum-ii-input-array-is-sorted/

https://leetcode.cn/problems/two-sum-ii-input-array-is-sorted/

https://leetcode-solution-leetcode-pp.gitbook.io/leetcode-solution/easy/167.two-sum-ii-input-array-is-sorted