main.java

		int distance = 10;
		int numberOfTiles = 2;
		int[] length = {1, 5};
		int[] cost = {1, 4};
		
		int cheapest = cheapest(distance, numberOfTiles, length, cost);  

wat.java

	public static int cheapest(int distance, int numberOfTiles, int[] length, int[] cost) {
		int[] c = new int[numberOfTiles];
		int min = 0;
		for (int p = 1; p <= distance; p++) {
			for (int i = 1; i <= numberOfTiles; i++) {
				if(cost[i] <= p){
					if(cost[i] + c[p - length[i]] < min){
						min = cost[i] + c[p - length[i]];	
					}	
				}
			}
			c[p] = min;
		}
		return c[numberOfTiles];
	}