蓝桥杯 算法训练 ALGO-124 数字三角形

 1 import java.io.BufferedReader;
 2 import java.io.IOException;
 3 import java.io.InputStreamReader;
 4 
 5 public class Main {
 6     private static int row;  //行数
 7     private static int[][] arr;
 8     public static void main(String[] args) throws NumberFormatException, IOException {
 9         BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
10         row = Integer.parseInt(br.readLine());
11         arr = new int[row][row];
12         
13         for(int i = 0; i < row; i++){
14             String[] str = br.readLine().split(" ");
15             for(int j = 0; j <= i; j++){
16                 arr[i][j] = Integer.parseInt(str[j]);
17             }
18         }
19         
20         int maxSum = maxSum(row,arr);
21         
22         System.out.println(maxSum);
23     }
24     /**
25      * 最大和
26      * @param row  行数
27      * @param arr  数组
28      * @return     该路径的最大和
29      */
30     private static int maxSum(int row, int[][] arr) {
31         for(int i = row-2; i >= 0; i--){
32             for(int j = 0; j <= i; j++){
33                 arr[i][j] += maxNum(arr[i+1][j] , arr[i+1][j+1]);
34             }
35         }
36         return arr[0][0];
37     }
38     
39     /**
40      * 求两个数中的最大数
41      * @param a
42      * @param b
43      * @return    最大数
44      */
45     private static int maxNum(int a, int b) {
46         return a>b?a:b;
47     }
48 }