paintHouse.js

// Paint House

// There are a row of n houses, each house can be painted with one of the three colors: red, blue or green. The cost of painting each house with a certain color is different. You have to paint all the houses such that no two adjacent houses have the same color.
// The cost of painting each house with a certain color is represented by a n x 3 cost matrix. For example, costs[0][0] is the cost of painting house 0 with color red; costs[1][2] is the cost of painting house 1 with color green, and so on... Find the minimum cost to paint all houses.

var minCost = function(costs) {
  if (!costs.length) {
    return 0;
  }
  let dp = [];
  dp.push(costs[0]);
  for (let i = 1; i < costs.length; i++) {
      dp.push(new Array(costs[i].length));
  }
  for (let i = 1; i < costs.length; i++) {
      dp[i][0] = costs[i][0] + Math.min(dp[i - 1][1], dp[i - 1][2]);
      dp[i][1] = costs[i][1] + Math.min(dp[i - 1][0], dp[i - 1][2]);
      dp[i][2] = costs[i][2] + Math.min(dp[i - 1][0], dp[i - 1][1]);
  }
  return Math.min(dp[dp.length - 1][0], dp[dp.length - 1][1], dp[dp.length - 1][2]);
};