class Solution { public: void replaceSpace(char *str,int length) { string str_2 = ""; int plus_length = 0; for(int i = 0;i<length;i++){ if(str[i] != ' '){ str_2 += str[i]; } else { str_2 += "%20"; plus_length += 2; } } length += plus_length; for(int j = 0;j<length;j++){ str[j] = str_2[j]; } } };