Leetcode 28. Implement StrStr ()

Implement strStr ().

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

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Implements a substring that determines whether a string is a string. If yes, returns the first occurrence of the substring if it is not returned-1;

This problem suddenly let me think of KMP algorithm, so to learn a bit KMP algorithm. (see article 1)

But KMP is very complex, especially that part of the matching table, so, I think of it.

Then I thought of this method.

Make up each kid string, and then the inventory matches.

classSolution { Public:    BOOLIssame (stringSstringt) {        if(s==t)return true; Else return false; }    intSTRSTR (stringHaystackstringneedle) {        intlen1=haystack.length (); intLen2=needle.length (); stringtmp=""; if(LEN2&GT;LEN1)return-1; if(len2==len1) {            if(Issame (Haystack,needle))return 0; Else return-1; }         for(intI=0; i<=len1-len2;i++) {tmp="";  for(intj=i;j<i+len2;j++) tmp+=Haystack[j]; if(Issame (Tmp,needle))returni; }        return-1; }};

Leetcode 28. Implement StrStr ()