#887 - Super Egg Drop - LeetCode JavaScript Solutions

#887 - Super Egg Drop

Problem Description

You are given k identical eggs and you have access to a building with n floors labeled from 1 to n.

You know that there exists a floor f where 0 <= f <= n such that any egg dropped at a floor higher than f will break, and any egg dropped at or below floor f will not break.

Each move, you may take an unbroken egg and drop it from any floor x (where 1 <= x <= n).

If the egg breaks, you can no longer use it. However, if the egg does not break, you may reuse it in future moves.

Return the minimum number of moves that you need to determine with certainty what the value of f is.

Solution

/**
 * @param {number} k
 * @param {number} n
 * @return {number}
 */
var superEggDrop = function(k, n) {
  const dp = new Array(k + 1).fill().map(() => new Array(n + 1).fill(0));

  function solve(eggs, floors) {
    if (floors === 0 || floors === 1) return floors;
    if (eggs === 1) return floors;
    if (dp[eggs][floors]) return dp[eggs][floors];

    let minMoves = floors;
    let low = 1;
    let high = floors;

    while (low <= high) {
      const middle = Math.floor((low + high) / 2);
      const breakCase = solve(eggs - 1, middle - 1);
      const noBreakCase = solve(eggs, floors - middle);
      const moves = 1 + Math.max(breakCase, noBreakCase);

      minMoves = Math.min(minMoves, moves);
      if (breakCase < noBreakCase) low = middle + 1;
      else high = middle - 1;
    }

    dp[eggs][floors] = minMoves;
    return minMoves;
  }

  return solve(k, n);
};