# 557. Reverse Words in a String III

題目：<https://leetcode.com/problems/reverse-words-in-a-string-iii/>

解法一：使用內建的 split 方法，分割出所有單字，最後將每個單字反轉後串接。

Python3：

class Solution:
    def reverseWords(self, s: str) -> str:
        tokens = s.split(' ')
        output = tokens[0][::-1]
        for t in tokens[1:]:
            output += ' ' + t[::-1]
        return output

if __name__ == '__main__':
    s = "Let's take LeetCode contest"

    ans = Solution().reverseWords(s)
    print(ans)

解法二：直接解，找出各個單字的頭尾，將每個單字反轉回來。

C：

#include <stdio.h>
#include <stdlib.h>
#include <string.h>

char * reverseWords(char * s) {
    int len = strlen(s), check, start, end;
    // reverse word
    check = 0;
    while (check < len - 1) {
        while (s[check] == ' ')
            check++;
        start = check;
        while (s[check] != ' ' && s[check] != '\0')
            check++;
        end = check - 1;
        while (start < end) {
            char tmp = s[start];
            s[start++] = s[end];
            s[end--] = tmp;
        }
    }
    return s;
}

int main() {
    char s[] = "Let's take LeetCode contest";
    
    char * ans = reverseWords(s);
    printf("%s|\n", ans);
    return 0;
}

###### tags: `leetcode` `string` `two pointers`