算法训练 数字三角形

import java.util.Scanner;

public class Main {
    static int[][] D = new int[101][101];
    static int N;

    public static int MaxSum(){
        for ( int i1 = N-1 ; i1 >= 1 ; i1--){
            for ( int j1 = 1 ; j1 <= i1 ; j1++){
                D[N][j1] = max(D[N][j1],D[N][j1+1]) + D[i1][j1];
            }
        }
        return D[N][1];
    }

    public static int max(int a , int b){
        return (a > b)?a:b;
    }

    public static void main(String[] args) {
        // TODO Auto-generated method stub
        Scanner in = new Scanner(System.in);
        N = in.nextInt();
        for ( int i = 1 ; i <= N ; i++){
            for ( int j = 1 ; j <= i ; j++){
                D[i][j] = in.nextInt();
            }
        }
        System.out.print(MaxSum());
        in.close();
    }

}