欧拉计划上的一道算法题。。求解

[ZHLEEBlander]

在以下这个20 20的网格中，四个处于同一对角线上的相邻数字用红色标了出来：
08 02 22 97 38 15 00 40 00 75 04 05 07 78 52 12 50 77 91 08
49 49 99 40 17 81 18 57 60 87 17 40 98 43 69 48 04 56 62 00
81 49 31 73 55 79 14 29 93 71 40 67 53 88 30 03 49 13 36 65
52 70 95 23 04 60 11 42 69 24 68 56 01 32 56 71 37 02 36 91
22 31 16 71 51 67 63 89 41 92 36 54 22 40 40 28 66 33 13 80
24 47 32 60 99 03 45 02 44 75 33 53 78 36 84 20 35 17 12 50
32 98 81 28 64 23 67 10 26 38 40 67 59 54 70 66 18 38 64 70
67 26 20 68 02 62 12 20 95 63 94 39 63 08 40 91 66 49 94 21
24 55 58 05 66 73 99 26 97 17 78 78 96 83 14 88 34 89 63 72
21 36 23 09 75 00 76 44 20 45 35 14 00 61 33 97 34 31 33 95
78 17 53 28 22 75 31 67 15 94 03 80 04 62 16 14 09 53 56 92
16 39 05 42 96 35 31 47 55 58 88 24 00 17 54 24 36 29 85 57
86 56 00 48 35 71 89 07 05 44 44 37 44 60 21 58 51 54 17 58
19 80 81 68 05 94 47 69 28 73 92 13 86 52 17 77 04 89 55 40
04 52 08 83 97 35 99 16 07 97 57 32 16 26 26 79 33 27 98 66
88 36 68 87 57 62 20 72 03 46 33 67 46 55 12 32 63 93 53 69
04 42 16 73 38 25 39 11 24 94 72 18 08 46 29 32 40 62 76 36
20 69 36 41 72 30 23 88 34 62 99 69 82 67 59 85 74 04 36 16
20 73 35 29 78 31 90 01 74 31 49 71 48 86 81 16 23 57 05 54
01 70 54 71 83 51 54 69 16 92 33 48 61 43 52 01 89 19 67 48
这四个数字的乘积是：26 63 78 14 = 1788696。在这个20 20网格中，处于任何方向上（上，下，左，右或者对角线）的四个相邻数字的乘积的最大值是多少？

[ZHLEEBlander]

555555555555555.。。。。。。。帮帮忙。。

[qybao]

自己遍历计算一下就好了

for example

import java.util.*;
public class Test {
    public static void main(String[] args) throws Throwable {
        int[][] matrix = {
            { 8,  2, 22, 97, 38, 15,  0, 40,  0, 75,  4,  5,  7, 78, 52, 12, 50, 77, 91,  8},
            {49, 49, 99, 40, 17, 81, 18, 57, 60, 87, 17, 40, 98, 43, 69, 48,  4, 56, 62,  0},
            {81, 49, 31, 73, 55, 79, 14, 29, 93, 71, 40, 67, 53, 88, 30,  3, 49, 13, 36, 65},
            {52, 70, 95, 23,  4, 60, 11, 42, 69, 24, 68, 56,  1, 32, 56, 71, 37,  2, 36, 91},
            {22, 31, 16, 71, 51, 67, 63, 89, 41, 92, 36, 54, 22, 40, 40, 28, 66, 33, 13, 80},
            {24, 47, 32, 60, 99,  3, 45, 02, 44, 75, 33, 53, 78, 36, 84, 20, 35, 17, 12, 50},
            {32, 98, 81, 28, 64, 23, 67, 10, 26, 38, 40, 67, 59, 54, 70, 66, 18, 38, 64, 70},
            {67, 26, 20, 68, 02, 62, 12, 20, 95, 63, 94, 39, 63,  8, 40, 91, 66, 49, 94, 21},
            {24, 55, 58,  5, 66, 73, 99, 26, 97, 17, 78, 78, 96, 83, 14, 88, 34, 89, 63, 72},
            {21, 36, 23,  9, 75,  0, 76, 44, 20, 45, 35, 14,  0, 61, 33, 97, 34, 31, 33, 95}, 
            {78, 17, 53, 28, 22, 75, 31, 67, 15, 94,  3, 80,  4, 62, 16, 14,  9, 53, 56, 92},
            {16, 39,  5, 42, 96, 35, 31, 47, 55, 58, 88, 24,  0, 17, 54, 24, 36, 29, 85, 57},
            {86, 56,  0, 48, 35, 71, 89,  7,  5, 44, 44, 37, 44, 60, 21, 58, 51, 54, 17, 58},
            {19, 80, 81, 68,  5, 94, 47, 69, 28, 73, 92, 13, 86, 52, 17, 77,  4, 89, 55, 40},
            { 4, 52,  8, 83, 97, 35, 99, 16,  7, 97, 57, 32, 16, 26, 26, 79, 33, 27, 98, 66},
            {88, 36, 68, 87, 57, 62, 20, 72,  3, 46, 33, 67, 46, 55, 12, 32, 63, 93, 53, 69},
            { 4, 42, 16, 73, 38, 25, 39, 11, 24, 94, 72, 18,  8, 46, 29, 32, 40, 62, 76, 36},
            {20, 69, 36, 41, 72, 30, 23, 88, 34, 62, 99, 69, 82, 67, 59, 85, 74,  4, 36, 16},
            {20, 73, 35, 29, 78, 31, 90,  1, 74, 31, 49, 71, 48, 86, 81, 16, 23, 57,  5, 54},
            { 1, 70, 54, 71, 83, 51, 54, 69, 16, 92, 33, 48, 61, 43, 52,  1, 89, 19, 67, 48}
        };


        Map<Integer, int[]> map = getMaxM(matrix, 4);
        for (Map.Entry<Integer, int[]> e : map.entrySet()) {
            for (int n : e.getValue()) {
                System.out.printf("%02d ", n);
            }
            System.out.println(e.getKey());
        }
    }

    public static Map<Integer, int[]> getMaxM(int[][] matrix, int size) {
        Map<Integer, int[]> map = new LinkedHashMap<Integer, int[]>(); 
        int[] tmp = new int[size];
        int m = 0, max = Integer.MIN_VALUE;
        for (int i=0; i<matrix.length; i++) {
            for (int j=0; j<matrix[i].length; j++) {
                if (j<=matrix[i].length-size) {
                    m = 1;
                    for (int k=0; k<size; k++) {
                        tmp[k] = matrix[i][j+k];
                        m *= tmp[k];
                    }
                    if (m > max) {
                        max = m;
                        map.clear();
                        map.put(m, Arrays.copyOf(tmp, size));
                    }
                }

                if (i<=matrix.length-size) {
                    m = 1;
                    for (int k=0; k<size; k++) {
                        tmp[k] = matrix[i+k][j];
                        m *= tmp[k];
                    }
                    if (m > max) {
                        max = m;
                        map.clear();
                        map.put(m, Arrays.copyOf(tmp, size));
                    }
                }
                
                if (i<=matrix.length-size && j<=matrix[i].length-size) {
                    m = 1;
                    for (int k=0; k<size; k++) {
                        tmp[k] = matrix[i+k][j+k];
                        m *= tmp[k];
                    }
                    if (m > max) {
                        max = m;
                        map.clear();
                        map.put(m, Arrays.copyOf(tmp, size));
                    }
                }

                if (i<=matrix.length-size && j>=size-1) {
                    m = 1;
                    for (int k=0; k<size; k++) {
                        tmp[k] = matrix[i+k][j-k];
                        m *= tmp[k];
                    }
                    if (m > max) {
                        max = m;
                        map.clear();
                        map.put(m, Arrays.copyOf(tmp, size));
                    }
                } 
            }
        }

        return map;
    }
}

[ssd189]

恩恩.

[富兰克陈]

没看明白题目的意思