1 class Solution {
 2 public:
 3     void replaceSpace(char *str,int length) {
 4         int len=0,clen=0;
 5         for(int i=0;str[i];++i)
 6         {
 7             len++;
 8             if(str[i]==' ') clen++;
 9         }
10         char *s=str+len;
11         char *cs=str+len+clen*2;
12         while(s<cs)
13         {
14             if(*s==' ')
15             {
16                 *cs--='0';
17                 *cs--='2';
18                 *cs--='%';
19             }
20             else *cs--=*s;
21             --s;
22         }
23     }
24 };