p018.java

/* 
 * Solution to Project Euler problem 18
 * By Nayuki Minase
 * 
 * http://nayuki.eigenstate.org/page/project-euler-solutions
 * https://github.com/nayuki/Project-Euler-solutions
 */


public final class p018 implements EulerSolution {
	
	public static void main(String[] args) {
		System.out.println(new p018().run());
	}
	
	
	public String run() {
		for (int i = triangle.length - 2; i >= 0; i--) {
			for (int j = 0; j < triangle[i].length; j++)
				triangle[i][j] += Math.max(triangle[i + 1][j], triangle[i + 1][j + 1]);  // Dynamic programming
		}
		return Integer.toString(triangle[0][0]);
	}
	
	
	private int[][] triangle = {
		{75},
		{95,64},
		{17,47,82},
		{18,35,87,10},
		{20,04,82,47,65},
		{19,01,23,75,03,34},
		{88,02,77,73,07,63,67},
		{99,65,04,28,06,16,70,92},
		{41,41,26,56,83,40,80,70,33},
		{41,48,72,33,47,32,37,16,94,29},
		{53,71,44,65,25,43,91,52,97,51,14},
		{70,11,33,28,77,73,17,78,39,68,17,57},
		{91,71,52,38,17,14,91,43,58,50,27,29,48},
		{63,66,04,68,89,53,67,30,73,16,69,87,40,31},
		{04,62,98,27,23, 9,70,98,73,93,38,53,60,04,23}
	};
	
}