Leetcode_07 integer [reverse]

Article Directory:

  • topic
  • A script and notes
  • A script logic

topic:

Gives a 32-bit signed integer, you need this integer number on each inverted.

Example 1:

Input: 123
Output: 321
 Example 2:

Input: -123
Output: -321
Example 3:

Input: 120
Output: 21
Note:

Suppose we have an environment can only store a 32-bit signed integer, then the value range of [-231 231--1]. Please According to this hypothesis, if integer overflow after reverse it returns 0.


And a script Note: When using [: 24ms]

class Solution: define a class #
     DEF Reverse (Self, X: int) -> int: # define a method and parameter 
        X1 = STR (X) shaping the # character variable into a variable
         IF  " - "  in X1: # determines whether the string with negative 
            X2 = X1 [. 1 :] # if so, using the method of slicing the first character string is removed, creating a new string 
            X3 = X2 [:: -. 1 ] # reverse text 
            X4 = int (X3) # string into a variable integer variable
             IF -X4 <-2 ** 31 is : # the title means, if the value of the reversed overflow 0 returns the
                 return (0)
             else:        
                 Return (- X4) # returns after inversion integer otherwise
         the else : 
            X2 = X1 [:: -. 1 ] # When the string with no negative sign "-", direct reversal string, and generates a new variable 
            X3 = int (x2) # new string variables into integer variable
             iF X3> 2 ** 31 is : # likewise determined whether the value obtained by inverting an overflow
                 return (0) # if the overflow, returns 0 if
             the else :
                 return (X3 ) # otherwise return value after reversal

Script logic:

  • This script first step you need to whether a negative sign "-" to judge, if with a minus sign, the corresponding processing is done
  • Step two: integer variable into a string variable
  • The third step: reverse a string variable
  • Step 4: after inversion into a string variable integer variable

 

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Origin www.cnblogs.com/mailong/p/12003117.html