Reverse Words in a String

Reverse Words in a String

Given an input string, reverse the string word by word.

For example,
Given s = "the sky is blue",
return "blue is sky the".

 

class Solution {
public:
    void reverseWords(string &s) {
        char c;
        int i,j,k;
        i = 0;
        while(s[i] == ' ')
         {
           s.erase(0,1);
         }
        int len = strlen(s.c_str());
        j = len-1;
        while (s[j] == ' ')
        {
            s.erase(j,1);
            j--;
        }
        len = strlen(s.c_str());
        i = 0;
        j = len-1;
        while (i < j)
        {
            c = s[i];
            s[i] = s[j];
            s[j] = c;
            i++;
            j--;
        }
        i = 0;
        while (true)
        {
            if (s[i] == '\0')
                break;
            while(s[i] == ' ')
                i++;
            j = i;
            while (s[j] != ' ' && s[j] != '\0')
                j++;
            k = i;
            i = j;
            j--;
            while (k < j)
            {
                c = s[k];
                s[k] = s[j];
                s[j] = c;
                k++;
                j--;
            }
        }
        for (i=1; i < len; i++)
        {
            if (s[i] == ' ' && s[i-1] == ' ')
               {
                   s.erase(i,1);
                    len--;
                    i--;
               }
        }
    }
}; 

 

记得先处理前后和中间多余的空格。