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

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Dungeon Game LeetCode Solution

Problem Statement

The demons had captured the princess and imprisoned her in the bottom-right corner of a dungeon. The dungeon consists of m x n rooms laid out in a 2D grid. Our valiant knight was initially positioned in the top-left room and must fight his way through dungeon to rescue the princess.

The knight has an initial health point represented by a positive integer. If at any point his health point drops to 0 or below, he dies immediately.

Some of the rooms are guarded by demons (represented by negative integers), so the knight loses health upon entering these rooms; other rooms are either empty (represented as 0) or contain magic orbs that increase the knight’s health (represented by positive integers).

To reach the princess as quickly as possible, the knight decides to move only rightward or downward in each step.

Return the knight’s minimum initial health so that he can rescue the princess.

Note that any room can contain threats or power-ups, even the first room the knight enters and the bottom-right room where the princess is imprisoned.

Example 1:

Input: dungeon = [[-2,-3,3],[-5,-10,1],[10,30,-5]]
Output: 7
Explanation: The initial health of the knight must be at least 7 if he follows the optimal path: RIGHT-> RIGHT -> DOWN -> DOWN.

Example 2:
Input: dungeon = [[0]]
Output: 1

Dungeon Game LeetCode Solution C++

class Solution {
public:
    int calculateMinimumHP(vector<vector<int>>& dungeon) {
        int n = dungeon.size(), m = dungeon[0].size();
        vector<vector<int>> memo(n, vector<int>(m, 1e9));
        memo[n - 1][m - 1] = dungeon[n - 1][m - 1] < 0 ? -dungeon[n - 1][m - 1] + 1 : 1;
        for(int i = n - 1; i >= 0; i--){
            for(int j = m - 1; j >= 0; j--){
                if(i < n - 1)
                    memo[i][j] = min(memo[i][j], max(1, memo[i + 1][j] - dungeon[i][j]));
                if(j < m - 1)
                    memo[i][j] = min(memo[i][j], max(1, memo[i][j + 1] - dungeon[i][j]));
            }
        }
        return memo[0][0];
    }
};Code language: PHP (php)

Dungeon Game LeetCode Solution Java

class Solution {
    public int calculateMinimumHP(int[][] dungeon) {
        int ans = calculateMinimumHP(dungeon,0,0);
        if(ans==0 && dungeon[0][0]<0) ans=dungeon[0][0];
        return ans>=0?1:-1*ans+1;
    }
    public int calculateMinimumHP(int[][] dungeon , int i, int j) {
        if(i==dungeon.length-1 && j==dungeon[0].length-1){
            return dungeon[i][j]>=0?0:dungeon[i][j];
        }
        if(i>=dungeon.length || j>=dungeon[0].length){
            return Integer.MIN_VALUE;
        }
        int bottom =  calculateMinimumHP(dungeon, i+1,j);
        int right = calculateMinimumHP(dungeon, i,j+1);
        int val=dungeon[i][j] + Math.max(bottom,right);
        return val>0?0:val;
    }
}Code language: PHP (php)

Dungeon Game LeetCode Solution JavaScript

var calculateMinimumHP = function(dungeon) {
    const n = dungeon.length;
    const m = dungeon[0].length;
    const dp = new Array(n).fill(0).map(() => new Array(m).fill(0));
    return helper(dungeon, n, m, 0, 0, dp);
};

var helper = function(dungeon, n, m, row, col, dp) {
    if (row === n - 1 && col === m - 1) {
        return Math.max(1, 1 - dungeon[row][col]);
    }
    if (row >= n || col >= m) {
        return Infinity;
    }
    if (dp[row][col] !== 0) {
        return dp[row][col];
    }
    const right = helper(dungeon, n, m, row, col + 1, dp);
    const down = helper(dungeon, n, m, row + 1, col, dp);
    dp[row][col] = Math.max(1, Math.min(right, down) - dungeon[row][col]);
    return dp[row][col];
};Code language: JavaScript (javascript)

Dungeon Game LeetCode Solution Python

class Solution(object):
    def calculateMinimumHP(self, dungeon):
        n = len(dungeon)
        m = len(dungeon[0])
        dp = [[0] * m for _ in range(n)]
        return self.helper(dungeon, n, m, 0, 0, dp)

    def helper(self, dungeon, n, m, row, col, dp):
        if row == n - 1 and col == m - 1:
            return max(1, 1 - dungeon[row][col])
        if row >= n or col >= m:
            return float('inf')
        if dp[row][col] != 0:
            return dp[row][col]
        right = self.helper(dungeon, n, m, row, col + 1, dp)
        down = self.helper(dungeon, n, m, row + 1, col, dp)
        dp[row][col] = max(1, min(right, down) - dungeon[row][col])
        return dp[row][col]