#2033 - Minimum Operations to Make a Uni-Value Grid

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Problem Description

You are given a 2D integer grid of size m x n and an integer x. In one operation, you can add x to or subtract x from any element in the grid.

A uni-value grid is a grid where all the elements of it are equal.

Return the minimum number of operations to make the grid uni-value. If it is not possible, return -1.

Solution

/**
 * @param {number[][]} grid
 * @param {number} x
 * @return {number}
 */
var minOperations = function(grid, x) {
  if (values.length === 1) return 0;
  const values = grid.flat();
  values.sort((a, b) => a - b);
  const median = values[Math.floor(values.length / 2)];
  let operations = 0;

  for (const value of values) {
    const diff = Math.abs(value - median);
    if (diff % x !== 0) return -1;
    operations += diff / x;
  }

  return operations;
};