Leetcode OJ : Implement strStr() [ Boyer–Moore string search algorithm ] python solution

 class Solution {
 public:
 int strStr(char *haystack, char *needle) {

     int i =  , skip[];
     char *str = haystack, *substr = needle;
     int len_src = strlen(str), len_sub = strlen(substr);
     // preprocess
     for (i = ; i < ; i++)
         skip[i] = len_sub;
     int last = len_sub - ;
     for (i = ; i < last;i++)
         skip[substr[i]] = last - i;
     // search
     int pos = ,  j;
     while (pos <= len_src-len_sub)  {
         j = last;
         while (j>= && str[pos+j]==substr[j])
             j--;
         if (j<)
              return pos;
         pos += skip[str[pos+last]];
     }
     return -;
 }
 };