题解 | #矩阵最长递增路径 与岛屿数量一致#

import java.util.*;


public class Solution {
    /**
     * 代码中的类名、方法名、参数名已经指定，请勿修改，直接返回方法规定的值即可
     * 递增路径的最大长度
     * @param matrix int整型二维数组 描述矩阵的每个数
     * @return int整型
     */
    public int solve (int[][] matrix) {
        // write code here
        int n = matrix.length;
        int m = matrix[0].length;
        int maxRes = 0;
        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                int temp = process(matrix, i, j, -1);
                maxRes = temp > maxRes ? temp : maxRes;
            }
        }
        return maxRes;
    }
    public static int process(int[][] matrix, int i, int j, int pre){
        if (i < 0 || i >= matrix.length ||
                j < 0 || j >= matrix.length ||
                matrix[i][j] <= pre) {
            return 0;
        }
        int max = 0;

        max = Math.max(process(matrix, i - 1, j, matrix[i][j]), max);
        max = Math.max(process(matrix, i + 1, j, matrix[i][j]), max);
        max = Math.max(process(matrix, i, j - 1, matrix[i][j]), max);
        max = Math.max(process(matrix, i, j + 1, matrix[i][j]), max);

        return max + 1;
    }
}