Leetcode 28. Implement StrStr ()

https://leetcode.com/problems/implement-strstr/

Implement strStr ().

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

• String simple question. Be sure to write no bugs.
• If the return statement is not written in the last line of the function, Leetcode will have runtime ERROR.

Line 27:control reaches end of non-void function [-werror=return-type]

• Strstr-c++ Reference
  • Http://www.cplusplus.com/reference/cstring/strstr/?kw=strstr

1#include <iostream>2#include <string>3 using namespacestd;4 5 classSolution {6  Public:7     intSTRSTR (stringHaystackstringneedle)8     {9         //Corner CaseTen         if(Needle.empty ())return 0; One         if(Haystack.empty ())return-1; A          -         intn = haystack.length ()-needle.length () +1; -  the         //better use < rather than <= -          for(inti =0; I < n; i + +) -         { -               BOOLFlag =true; +                -                for(intj =0; J < Needle.length (); J + +) +               { A                   if(Haystack.at (i + j)! =needle.at (j)) at                   { -Flag =false; -                      Break; -                   } -               } -                in               if(flag) -                  returni; to         } +          -         return-1; the     }     * }; $ Panax Notoginseng intMain () - { the solution testsolution; +     stringS1 ="Mississippi"; A     stringS2 ="ISSI"; the      +cout << testsolution.strstr (S1, S2) <<Endl; -      $ GetChar (); $      -     return 0; -}

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Leetcode 28. Implement StrStr ()