# LeetCode – Paint House (Java)

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 is the cost of painting house 0 with color red; costs is the cost of painting house 1 with color green, and so on... Find the minimum cost to paint all houses.

Java Solution

A typical DP problem.

```public int minCost(int[][] costs) { if(costs==null||costs.length==0) return 0;   for(int i=1; i<costs.length; i++){ costs[i] += Math.min(costs[i-1], costs[i-1]); costs[i] += Math.min(costs[i-1], costs[i-1]); costs[i] += Math.min(costs[i-1], costs[i-1]); }   int m = costs.length-1; return Math.min(Math.min(costs[m], costs[m]), costs[m]); }```

Or a different way of writing the code without original array value changed.

```public int minCost(int[][] costs) { if(costs==null||costs.length==0){ return 0; }   int[][] matrix = new int[costs.length];   for(int j=0; j<costs.length; j++){ if(j==0){ matrix[j]=costs[j]; matrix[j]=costs[j]; matrix[j]=costs[j]; }else{ matrix[j]=Math.min(matrix[j-1], matrix[j-1])+costs[j]; matrix[j]=Math.min(matrix[j-1], matrix[j-1])+costs[j]; matrix[j]=Math.min(matrix[j-1], matrix[j-1])+costs[j]; } }   int result = Math.min(matrix[costs.length-1], matrix[costs.length-1]); result = Math.min(result, matrix[costs.length-1]);   return result; }```
Category >> Algorithms
If you want someone to read your code, please put the code inside <pre><code> and </code></pre> tags. For example:
```<pre><code>
String foo = "bar";
</code></pre>
```
• Sarthak Sota

..