Given two strings needle and haystack, return the index of the first occurrence of needle in haystack, or -1 if needle is not part of haystack.

gistfile1.txt

class Solution:
    def strStr(self, haystack: str, needle: str) -> int:
        x = [a for a in haystack]
        y = [b for b in needle]
        k = -1       
        if len(y) <= len(x):            
            for i in range(len(x)-len(y)+1):
                if x[i] == y[0]:
                    for j in range(len(y)):
                        if x[i+j] == y[j]:
                            k = i
                        else:
                            k = -1
                            break
                if k!= -1:
                    break                      
        return k
    pass
ret = Solution().strStr("apple","sdddd")