151. Reverse Words in a String

字符串里的单词反转

转为数组

• 时间复杂度O(N)，空间复杂度O(N)
• Runtime: 72 ms, faster than 96.97%
• Memory Usage: 40.5 MB, less than 35.39%

/**
 * @param {string} s
 * @return {string}
 */
var reverseWords = function(s) {
    return s.split(' ').filter(i => i.length).reverse().join(' ')
};

正则

• Runtime: 72 ms, faster than 96.97%
• Memory Usage: 40.7 MB, less than 24.93%

/**
 * @param {string} s
 * @return {string}
 */
var reverseWords = function(s) {
    return s.match(/[\S]+/g).reverse().join(' ')
     // return s.match(/[\S]+/ig).reverse().join(" ")
};

手动实现

• Runtime: 88 ms, faster than 36.56%
• Memory Usage: 41 MB, less than 13.20%

/**
 * @param {string} s
 * @return {string}
 */
var reverseWords = function(s) {
    let match = s.match(/[\S]+/g)
    let res = ''
    console.log(match)
    while(match.length > 0) {
        if(!res) res = match.shift() + res
        else res = (match.shift() + ' ') + res
        // console.log(res)
    }
    return res
};