Solution to http://100.70.19.162:8000/contest/32/7

dirty_stack.py

import sys

"""
  Solution to http://100.70.19.162:8000/contest/32/7
"""

stack = list(map(int, sys.stdin.read().splitlines()))
del stack[0]
stack = [(i, True) for i in stack]

popped = []
while stack:
    val = stack[0][0]
    if val >= len(stack) or not stack[val][1]:
        popped.append(stack.pop(0)[0])
    else:
        stack[0], stack[val] = stack[val], (val, False)
print(','.join(map(str, popped)))