Suppose we have a list of numbers called candies and someone is playing a game against his/her friend. In each round, a player can remove any two consecutive candies with the same value. And whoever can not pick up a candy loses and that player1 start first, we have to check whether player1 will win or not.
So, if the input is like nums = [2, 2, 5], then the output will be True, as if player1 picks the 2s then the other player cannot pick any candies.
To solve this, we will follow these steps:
stack := a new stack
turns := 0
for each num in nums, do
if stack is not empty and top of stack is same as num, then
pop from stack
turns := turns + 1
otherwise,
push num into stack
return true when turns is odd otherwise false
Example
class Solution: def solve(self, nums): stack = [] turns = 0 for num in nums: if stack and stack[-1] == num: stack.pop() turns += 1 else: stack.append(num) return bool(turns & 1) ob = Solution() nums = [2, 2, 5] print(ob.solve(nums))
Input
[2, 2, 5]
Output
True