1535. Find the Winner of an Array Game

Problem Link

Description

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Given an integer array arr of distinct integers and an integer k.

A game will be played between the first two elements of the array (i.e. arr[0] and arr[1]). In each round of the game, we compare arr[0] with arr[1], the larger integer wins and remains at position 0, and the smaller integer moves to the end of the array. The game ends when an integer wins k consecutive rounds.

Return the integer which will win the game.

It is guaranteed that there will be a winner of the game.

 

Example 1:

Input: arr = [2,1,3,5,4,6,7], k = 2
Output: 5
Explanation: Let's see the rounds of the game:
Round |       arr       | winner | win_count
  1   | [2,1,3,5,4,6,7] | 2      | 1
  2   | [2,3,5,4,6,7,1] | 3      | 1
  3   | [3,5,4,6,7,1,2] | 5      | 1
  4   | [5,4,6,7,1,2,3] | 5      | 2
So we can see that 4 rounds will be played and 5 is the winner because it wins 2 consecutive games.

Example 2:

Input: arr = [3,2,1], k = 10
Output: 3
Explanation: 3 will win the first 10 rounds consecutively.

 

Constraints:

• 2 <= arr.length <= 105
• 1 <= arr[i] <= 106
• arr contains distinct integers.
• 1 <= k <= 109

Solution

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Python3

class Solution:
    def getWinner(self, arr: List[int], k: int) -> int:
        N = len(arr)
        curr = arr[0]
        count = 0
 
        # the winner will always be max(A) if the winner is not decided after one pass coz no one can beat him
 
        for i in range(1, N):
            if arr[i] > curr:
                curr = arr[i]
                count = 0
 
            count += 1
 
            if count == k: break
        
        return curr
 

C++

class Solution {
public:
    int getWinner(vector<int>& arr, int k) {
        for (int i=1, j=0; i < arr.size() && j < k; ++i){
            if (arr[0] > arr[i])
                ++j;
            else{
                swap(arr[0], arr[i]);
                j = 1;
            }
                
        }
        
        return arr[0];
    }
};