SPOJ Problem Set (classical)

2021. Moving Pebbles

Problem code: PEBBMOV

A Game of Moving Pebbles

Problem

Two players play the following game. At the beginning of the game they start with n (1<=n<=100000) piles of stones. At each step of the game, the player chooses a pile and remove at least one stone from this pile and move zero or more stones from this pile to any other pile that still has stones. A player loses if he has no more possible moves. Given the initial piles, determine who wins: the first player, or the second player, if both play perfectly.

The Input

Each line of input has integers 0 < n <= 100000, followed by n positive integers denoting the initial piles.

The Output

For each line of input, output "first player" if first player can force a win, or "second player", if the second player can force a win.

Sample Input

3 2 1 3

Sample Output

first player

Problemsetter --- Chen, Jiahong

Added by:	Chen Xiaohong
Date:	2007-11-06
Time limit:	5s
Source limit:	50000B
Languages:	All except: CLOJ ERL F# JS PERL 6 TECS

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2010-06-18 08:42:10 刘启鹏 "integers" may be very large.
2010-01-22 00:33:41 Jorge Enrique Moreira Broche It is not clear in the text, but you can move stones from one pile to more than one other pile provided they already have stones