题解 | #矩阵最长递增路径#

using System;
using System.Collections.Generic;


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
     */
    int[,] memory;
    List<List<int>> matrix;
    int m,n;
    public int solve (List<List<int>> matrix) {
        this.matrix = matrix;
        m = matrix.Count;
        n = matrix[0].Count;
        memory = new int[m,n];
        int res = 0;
        for(int i = 0; i < m; i++){
            for(int j = 0; j < n;j++){
                res = Math.Max(res, Search(i,j));
                //Console.WriteLine(memory[i,j]);
            }
        }
        return res;
    }
    public int Search(int x, int y){
        if(memory[x,y] != 0) return memory[x,y];
        memory[x,y] = 1;
        if(x > 0 && matrix[x][y] < matrix[x - 1][y]) memory[x,y] = Math.Max(memory[x,y],Search(x - 1, y)+1);
        if(y > 0 && matrix[x][y] < matrix[x][y - 1]) memory[x,y] = Math.Max(memory[x,y],Search(x, y - 1)+1);
        if(x < m-1 && matrix[x][y] < matrix[x + 1][y]) memory[x,y] = Math.Max(memory[x,y],Search(x + 1, y)+1);
        if(y < n-1 && matrix[x][y] < matrix[x][y + 1]) memory[x,y] = Math.Max(memory[x,y],Search(x, y + 1)+1);

        return memory[x,y];
    }
}