557. Reverse Words in a String I

Given a string, you need to reverse the order of characters in each word within a sentence while still preserving whitespace and initial word order.

Example 1:

Input: "Let's take LeetCode contest"
Output: "s'teL ekat edoCteeL tsetnoc"

Note: In the string, each word is separated by single space and there will not be any extra space in the string.

c语言实现

char* reverseWords(char* s) {
    int start = 0;
    // char temp;
    int len = strlen(s); //这个不放在外面就会超时
    for(int i = 0;i<=len;i++){//注意这里的i<=strlen(s) 对于一个字符串的最后一位是'\0'所以下标要多，才能遍历到那一位
        if(s[i] == ' ' || s[i] == '\0'){
            int end = i-1;
            int size = (start + end) / 2;
            for(int j = start;j <= size;j++){ //双数的是要小于等于
                char temp = s[j];
                s[j] = s[end];
                s[end] = temp;
                end = end -1;
            }
            start = i + 1;
        }
    }
    return s;
}

遇到一个问题，之前是for (int i = 0;i<=strlen(s);i++)
提交之后报超时，放在外面就不报了，不知到为啥····
python实现

class Solution(object):
    def reverseWords(self, s):
        """
        :type s: str
        :rtype: str
        """
        a = s.split(' ')
        b = []
        for i in a:
            b.append(i[::-1])
        c = ' '.join(b) 
        return str(c)

写完之后发现和刘老师写的一样，厉害了
第一次提交出错，是用了 return str(b)
循环之后 b 变为['god', 'sevol', 'gip']
str(b) "['god', 'sevol', 'gip']"
然后查了下list怎么变str
但是str变list

>>>str = 'abcde'
>>>a = list(str)
>>>a
>>>['a','b','c','d','e']