comefrom: <qiyuangong>028_Implement_strStr()_1.py
code: def strStr( haystack, needle):
      lsh, lsn = len(haystack), len(needle)
      if lsn == 0:
          return 0
      pos, index = 0, 0
      while index <= lsh - lsn:
          if haystack[index] == needle[pos]:
              backup = index
              while index < lsh and pos < lsn and haystack[index] == needle[pos]:
                  pos += 1
                  index += 1
              if pos == len(needle):
                  return index - pos
              index = backup
          index += 1
          pos = 0
      return -1
masked: def sample_funcname ( var_0 , var_1 ) :
      var_3 , var_4 = len ( var_0 ) , len ( var_1 )
      if var_4 == 0 :
          return 0
      var_6 , var_7 = 0 , 0
      while var_7 <= var_3 - var_4 :
          if var_0 [ var_7 ] == var_1 [ var_6 ] :
              var_8 = var_7
              while var_7 < var_3 and var_6 < var_4 and var_0 [ var_7 ] == var_1 [ var_6 ] :
                  var_6 += 1
                  var_7 += 1
              if var_6 == len ( var_1 ) :
                  return var_7 - var_6
              var_7 = var_8
          var_7 += 1
          var_6 = 0
      return - 1
  