LeetCode 557. Reverse Words in a String III

557. Reverse Words in a String III

Description

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.

ExampleInput: "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. 

Solution

// 题目意思就是将用空格间隔的各个单词逆转过来//我起初一直tle超时，后来发现根源在循环终止条件 i<=strlen(s) 这是我一个有时考虑有有时不考虑的一个问题，如果这么写的话，每次循环都会判断，非常浪费时间//思路就是每次碰到间隔符或者结束符，就把之前的一个单词逆转过来，代码如下char* reverseWords(char* s) {    int begin = 0,len = strlen(s);     for (int i = 0;i <= len;i++) {    //就是这里，不要写成i <= strlen(s);        if (s[i] == ' ' || s[i] == '\0') {            int temp = i - 1;            while (begin < temp) {                char t = s[begin];                s[begin] = s[temp];                s[temp] = t;                begin++;                temp--;            }            begin = i + 1;        }    }    return s;}