codewars练习（javascript）-2021/3/23

文章目录

codewars-js练习
- 2021/3/23
- - github 地址
  - 【1】<8kyu>【Fake Binary】
  - 【2】<8kyu>【My head is at the wrong end!】
  - 【3】<5kyu>【Maximum subarray sum】

codewars-js练习

2021/3/23

github 地址

my github地址，上面有做的习题记录，不断更新…

【1】<8kyu>【Fake Binary】

Given a string of digits, you should replace any digit below 5 with ‘0’ and any digit 5 and above with ‘1’. Return the resulting string.

用’0’代替5以下的数字，用’1’代替5以上的数字。

example：

'45385593107843568'// '01011110001100111'

solution

<script type="text/javascript">function fakeBin(x){// console.log(x)x = x.replace(/[1-4]/g,'0')return x.replace(/[^0-4]/g,'1')}// 验证console.log(fakeBin('45385593107843568'));// '01011110001100111'
</script>

【2】<8kyu>【My head is at the wrong end!】

你会得到一个有三个值的数组(tail, body, head)。你的工作是重新安排排列，使动物是正确的方式(头，身体，尾巴)。

example：

["tail", "body", "head"]), ["head", "body", "tail"]);
["ground", "rainbow", "sky"]), ["sky", "rainbow", "ground"]);

solution

<script type="text/javascript">function fixTheMeerkat(arr) {return arr.reverse()}// 验证console.log(fixTheMeerkat(["tail", "body", "head"]));// ["head", "body", "tail"]console.log(fixTheMeerkat(["tails", "body", "heads"]));// ["heads", "body", "tails"]console.log(fixTheMeerkat(["bottom", "middle", "top"]));//["top", "middle", "bottom"]console.log(fixTheMeerkat(["lower legs", "torso", "upper legs"]));// ["upper legs", "torso", "lower legs"]console.log(fixTheMeerkat(["ground", "rainbow", "sky"]));// ["sky", "rainbow", "ground"]
</script>

【3】<5kyu>【Maximum subarray sum】

The maximum sum subarray problem consists in finding the maximum sum of a contiguous subsequence in an array or list of integers

example：

maxSequence([-2, 1, -3, 4, -1, 2, 1, -5, 4])
// should be 6: [4, -1, 2, 1]

用for循环遍历数组arr，每次取到一个元素后，加到maxTemp中，然后判断maxTemp，若小于0，则将maxTemp设置为0，否则不变。然后去maxTemp和maxRes的最大值赋给maxRes用于返回。

solution

<script type="text/javascript">var maxSequence = function(arr){// console.log(arr)if(arr.length ==0)return 0;var maxTemp = 0;var max = 0;for(var k of arr){maxTemp += k;if(maxTemp <0)maxTemp = 0;max = max >= maxTemp? max : maxTemp;}return max}// 验证console.log(maxSequence([]));//0console.log(maxSequence([-2, 1, -3, 4, -1, 2, 1, -5, 4]));// 6
</script>