Last updated on July 18th, 2024 at 02:33 am

Here, We see Predict the Winner LeetCode Solution. This Leetcode problem is done in many programming languages like C++, Java, JavaScript, Python, etc. with different approaches.

List of all LeetCode Solution

Topics

Dynamic Programming, Minimax

Companies

Google

Level of Question

Medium

Predict the Winner LeetCode Solution

Problem Statement

You are given an integer array nums. Two players are playing a game with this array: player 1 and player 2.

Player 1 and player 2 take turns, with player 1 starting first. Both players start the game with a score of 0. At each turn, the player takes one of the numbers from either end of the array (i.e., nums[0] or nums[nums.length – 1]) which reduces the size of the array by 1. The player adds the chosen number to their score. The game ends when there are no more elements in the array.

Return true if Player 1 can win the game. If the scores of both players are equal, then player 1 is still the winner, and you should also return true. You may assume that both players are playing optimally.

Example 1:
Input: nums = [1,5,2]
Output: false
Explanation: Initially, player 1 can choose between 1 and 2. If he chooses 2 (or 1), then player 2 can choose from 1 (or 2) and 5. If player 2 chooses 5, then player 1 will be left with 1 (or 2). So, final score of player 1 is 1 + 2 = 3, and player 2 is 5. Hence, player 1 will never be the winner and you need to return false.

Example 2:
Input: nums = [1,5,233,7]
Output: true
Explanation: Player 1 first chooses 1. Then player 2 has to choose between 5 and 7. No matter which number player 2 choose, player 1 can choose 233. Finally, player 1 has more score (234) than player 2 (12), so you need to return True representing player1 can win.

1. Predict the Winner LeetCode Solution C++

class Solution {
    bool checkWin(int ans,int total){
	   return ans>=total-ans;
    }
    int maxScore(vector<int>&A,int total,int i,int j){
        if(i>j)
            return 0;
      return total-min(maxScore(A,total-A[i],i+1,j),maxScore(A,total-A[j],i,j-1));
    }
public:
    bool predictTheWinner(vector<int>& nums) {
        int total=0;
        for(auto x:nums)
            total+=x;
        return checkWin(maxScore(nums,total,0,nums.size()-1),total);
    }
};

2. Predict the Winner LeetCode Solution Java

class Solution {
    int[][] dp;
    private int score(int[] nums, int l, int r) {
        if (dp[l][r] != -1) {
            return dp[l][r];
        }
        if (l == r) {
            return nums[l];
        }
        int left = nums[l] - score(nums, l + 1, r);
        int right = nums[r] - score(nums, l, r - 1);
        dp[l][r] = Math.max(left, right);
        return dp[l][r];
    }
    
    public boolean predictTheWinner(int[] nums) {
        int n = nums.length;
        dp = new int[n][n];
        for (int i = 0; i < n; ++i) {
            Arrays.fill(dp[i], -1);
        }
        return score(nums, 0, n - 1) >= 0;
    }
}

3. Predict the Winner Leetcode Solution JavaScript

var predictTheWinner = function(nums) {
    const n = nums.length;
    const dp = Array.from(Array(n), () => Array(n).fill(0));
    for (let i = n-1; i >= 0; --i) {
        for (let j = i; j < n; ++j) {
            if (i == j) {
                dp[i][j] = nums[i];
            } else {
                dp[i][j] = Math.max(nums[i] - dp[i+1][j], nums[j] - dp[i][j-1]);
            }
        }
    }
    return dp[0][n-1] >= 0;
};

4. Predict the Winner Leetcode Solution Python

class Solution(object):
    def predictTheWinner(self, nums):
        n = len(nums)
        dp = [[-1 for _ in range(n)] for _ in range(n)]
        return self.score(nums, 0, n - 1, dp) >= 0

    def score(self, nums, l, r, dp):
        if dp[l][r] != -1:
            return dp[l][r]
        if l == r:
            return nums[l]
        left = nums[l] - self.score(nums, l + 1, r, dp)
        right = nums[r] - self.score(nums, l, r - 1, dp)
        dp[l][r] = max(left, right)
        return dp[l][r]