思想

java 代码

import java.io.*;
import java.lang.*;

class Main{
    static int n = 0, N = 510;
    static int[][] a = new int[N][N], f = new int[N][N];
    public static void main(String[] args)throws Exception{
        BufferedReader buf = new BufferedReader(new InputStreamReader(System.in));
        n = Integer.valueOf(buf.readLine());
        for(int i = 1; i <= n; ++i){
            String[] info = buf.readLine().split(" ");
            for(int j = 1; j <= i; ++j){
                a[i][j] = Integer.valueOf(info[j - 1]);
            }
        }

        for(int i = n - 1; i >= 0;--i){
            for(int j = 1; j <= i + 1; ++j){
                a[i][j] = Math.max(a[i + 1][j], a[i + 1][j + 1]) + a[i][j];
            }
        }

        System.out.print(a[1][1]);

    }
}