[C + +] Implement StrStr ()

Implement strStr ().

Return the index of the first occurrence of needle in haystack, or-1 if needle are not part of haystack.

Example 1:

Input:haystack = "Hello", needle = "ll" Output:2

Example 2:

Input:haystack = "AAAAA", needle = "BBA" Output: 1

The STRSTR () function returns a matching first character index.

Conventional matching algorithms can be used, brute force algorithm

Traverse Haystack to m-n+1 while traversing needle from 0 to N,while to determine whether two string corresponding characters are equal.

classSolution { Public:    intSTRSTR (stringHaystackstringneedle) {        intm = Haystack.size (), n =needle.size (); if(n = =0)            return 0;  for(inti =0; I < M-n +1; i++) {            intj =0;  while(Haystack[i + j] = =Needle[j]) {J++; if(J = =N)returni; } J++; }        return-1; }};//6 Ms

[C + +] Implement StrStr ()