해커랭크 hackerrank Super Reduced String

Reduce a string of lowercase characters in range ascii[‘a’..’z’]by doing a series of operations. In each operation, select a pair of adjacent letters that match, and delete them.

Delete as many characters as possible using this method and return the resulting string. If the final string is empty, return Empty String

Example.

 

aab shortens to b in one operation: remove the adjacent a characters.

 

Remove the two 'b' characters leaving 'aa'. Remove the two 'a' characters to leave ''. Return 'Empty String'.

Function Description

Complete the superReducedString function in the editor below.

superReducedString has the following parameter(s):

• string s: a string to reduce

Returns

• string: the reduced string or Empty String

Input Format

A single string, .

Constraints

•  

Sample Input 0

aaabccddd

Sample Output 0

abd

Explanation 0

Perform the following sequence of operations to get the final string:

aaabccddd → abccddd → abddd → abd

Sample Input 1

aa

Sample Output 1

Empty String

Explanation 1

aa → Empty String

Sample Input 2

baab

Sample Output 2

Empty String

Explanation 2

baab → bb → Empty String

#!/bin/python3

import math
import os
import random
import re
import sys

#
# Complete the 'superReducedString' function below.
#
# The function is expected to return a STRING.
# The function accepts STRING s as parameter.
#

def superReducedString(s):
    # Write your code here


    stack = []
    for i in range(len(s)):
        if len(stack) == 0 or s[i] != stack[-1]:
            stack.append(s[i])
        else:
            stack.pop()
    return 'Empty String' if len(stack) == 0 else ''.join(stack)
            
    

if __name__ == '__main__':
    fptr = open(os.environ['OUTPUT_PATH'], 'w')

    s = input()

    result = superReducedString(s)

    fptr.write(result + '\n')

    fptr.close()