编程之reverseWords

模仿答案：

class Solution {public:    string reverseWords(string s) {        int front = 0;                         int str_length = s.length();          for(int i = 0; i <= str_length; i++) {            if(i == s.length() || s[i] == ' ') {                   reverse(&s[front], &s[i]);                front = i + 1;                     }        }        return s;    }};

写到vs里面：

定义字符串    s 和 p 调用reverseWords

 #include<iostream> #include<sstream>using namespace std;string reverseWords(string s) {int start = 0, end = 0, n = s.size();while (start < n && end < n) {while (end < n && s[end] != ' ') ++end;for (int i = start, j = end - 1; i < j; ++i, --j) {swap(s[i], s[j]);}start = ++end;}return s;}int main(){          string s = "Let's take LeetCode contest";  string p;  p =reverseWords(s);  cout <<p<<endl;  return 0;}

注：上次提到的#include<sstream>可以代替#include<string>

amazing!!!!!!!!!!!!!!!!

  他说可以用reverse函数，找到空格或最后字符时将空格前的字符转置，front+1是每个字符串的首字符。

reverse(beg,end)

reverse_copy(sourceBeg,sourceEnd,destBeg)

reverse()会将区间[beg,end)内的元素全部逆序；

reverse_copy()会将源区间[sourceBeg,sourceEnd)内的元素复制到"以destBeg起始的目标区间"，并在复制过程中颠倒安置次序；

reverse_copy()返回目标区间内最后一个被复制元素的下一个位置，也就是第一个未被覆盖的元素；

代码

#include<iostream>#include<string>using namespace std;string reverseWords(string s) {int front = 0;int str_length = s.length();for (int i = 0; i <= str_length; i++) {if (i == s.length() || s[i] == ' ') {reverse(&s[front], &s[i]);front = i + 1;}}return s;}int main(){      string s = "Let's take LeetCode contest";  string p;  p =reverseWords(s);  cout <<p<<endl;  return 0;}