记忆化搜索（Java）

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​​蓝桥杯算法竞赛大纲​​​​数论相关（Java）​​​​​​

​​枚举相关（Java）​​​​​​

​​对象排序（Java）​​​​​​

​​字符串相关（Java）​​

​​​排序相关算法（Java）​​​

记忆化搜索（Java）
​​​树论相关（Java）​​

​​​图论相关（Java）​​

​​​堆（Java）​​​​贪心（Java）​​

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package 搜索;

import java.util.Scanner;

// https://www.luogu.com.cn/problem/P1434
public class _记忆化搜索 {

    static int m, n;
    static int max = -1;
    static int[] dx = {1, -1, 0, 0};
    static int[] dy = {0, 0, 1, -1};
    static int[][] arr;
    static int[][] cache;

    public static void main(String[] args) {

        Scanner scan = new Scanner(System.in);

        n = scan.nextInt();
        m = scan.nextInt();
        arr = new int[n][m];
        cache = new int[n][m];

        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                arr[i][j] = scan.nextInt();
            }
        }

        for (int i = 0; i < n; i++) {
            for (int j = 0; j < m; j++) {
                max = Math.max(max, dfs(i, j));
            }
        }

        System.out.println(max);
    }

    public static int dfs(int x, int y) {

        if (cache[x][y]!=0){
            return cache[x][y];
        }

        int t = 0;

        for (int k = 0; k < 4; k++) {

            int xx = x + dx[k];
            int yy = y + dy[k];
            if (xx<0||yy<0||xx>=n||yy>=m||arr[x][y]<=arr[xx][yy]){
                continue;
            }

            t = Math.max(t, dfs(xx, yy));
        }

        cache[x][y] = t + 1;
        return t + 1;
    }
}