Dungeon Game LeetCode solution in JavaScript

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/**
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 * The dynamic programming solution.
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 *
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 * Time Complexity:  O(m*n)
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 * Space Complexity: O(1)
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 *
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 * @param {number[][]} dungeon
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 * @return {number}
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 */
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var calculateMinimumHP = function (dungeon) {
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  const m = dungeon.length;
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  const n = dungeon[0].length;
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  const ii = m - 1;
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  const jj = n - 1;
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  for (let i = ii; i >= 0; i--) {
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    for (let j = jj; j >= 0; j--) {
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      if (i < ii || j < jj) {
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        const hc = dungeon[i][j];
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        const hp1 = i < ii ? Math.min(hc, hc + dungeon[i + 1][j]) : -Infinity;
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        const hp2 = j < jj ? Math.min(hc, hc + dungeon[i][j + 1]) : -Infinity;
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        dungeon[i][j] = Math.max(hp1, hp2);
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      }
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    }
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  }
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  return Math.max(1 - dungeon[0][0], 1);
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};