改变一个布尔值使连在一起的true的数量最多并找出那个位置

Question

给出一个boolean类型的二维数组，
只有上下左右可以连接，比如上图改变第三行第二列的布尔值可以使连在一起的true数量最大为10，同数量时优先上然后左，该如何找出该位置

Answer 1

完整算法代码如下：

public class Answer7720122 {

    public static void main(String[] args) {
        boolean[][] ccMatrix = {
                {true, false, true, true},
                {true, false, true, false},
                {true, false, true, false},
                {false, true, false, true},
                {false, true, false, true},
                {true, false, false, true}};

        Map<String, Integer> ijCount = new HashMap<>();
        for(int i=0; i<ccMatrix.length; ++i) {
            for(int j=0; j<ccMatrix[i].length; ++j) {
                if(!ccMatrix[i][j]) {
                    ccMatrix[i][j] = true;
                    List<String> tempList = new ArrayList<>();
                    AtomicInteger count = new AtomicInteger(0);
                    count(ccMatrix, tempList, count, i, j, 1);
                    count(ccMatrix, tempList, count, i, j, 2);
                    count(ccMatrix, tempList, count, i, j, 3);
                    count(ccMatrix, tempList, count, i, j, 4);
                    ijCount.put(i+""+j, count.get());
                    ccMatrix[i][j] = false;
                }
            }
        }
        List<Integer> count = ijCount.values().stream().sorted().collect(Collectors.toList());
        int max = count.get(count.size()-1);
        for(Map.Entry<String, Integer> entry : ijCount.entrySet()) {
            if(max == entry.getValue()) {
                String key = entry.getKey();
                System.out.println("修改第"+key.charAt(0)+"行第"+key.charAt(1)+"列可得到最大为"+max);
            }
        }
        System.out.println("注意：行和列均从0开始计数！");
    }

    /**
     *
     * @param arr
     * @param tempList
     * @param count
     * @param i
     * @param j
     * @param direction 递归方向。1：上左；2：上右；3：下左；4：下右；
     */
    private static void count(boolean[][] arr, List<String> tempList, AtomicInteger count, int i, int j, int direction) {
        int row = arr.length;
        int col = arr[0].length;
        if(i<0 || j<0 || i>=row || j>=col) {
            return;
        }
        if(!arr[i][j]) {
            return;
        }
        if(arr[i][j]) {
            String key = i+""+j;
            if(!tempList.contains(key)) {
                tempList.add(key);
                count.addAndGet(1);
            }
        }
        switch (direction) {
            case 1:
                count(arr, tempList, count, i-1, j, direction);
                count(arr, tempList, count, i, j-1, direction);
                break;
            case 2:
                count(arr, tempList, count, i-1, j, direction);
                count(arr, tempList, count, i, j+1, direction);
                break;
            case 3:
                count(arr, tempList, count, i+1, j, direction);
                count(arr, tempList, count, i, j-1, direction);
                break;
            case 4:
                count(arr, tempList, count, i+1, j, direction);
                count(arr, tempList, count, i, j+1, direction);
                break;
        }
    }
}

运行结果如下:

修改第2行第1列可得到最大为10
修改第3行第2列可得到最大为10
注意：行和列均从0开始计数！

调试了很久，请采纳，十分感谢！
希望可以额外多加几个鸡腿！