哈哈哈

#include <iostream>
#include <vector>
#include <queue>
using namespace std;

// 定义二维数组的行和列的最大值
const int MAX_R = 100;
const int MAX_C = 100;

// 定义上、下、左、右四个方向的坐标变化
const int dx[4] { -1, 1, 0, 0 };
const int dy[4] { 0, 0, -1, 1 };

int R, C; // 行数和列数
int arr[MAX_R][MAX_C]; // 存储二维数组的值
int dp[MAX_R][MAX_C]; // 存储以每个位置为起点的最长下降路径长度

int dfs(int x, int y) {
if (dp[x][y] > 0) {
return dp[x][y];
}

int max_length = 1;

for (int i = 0; i < 4; i++) {
    int nx = x + dx[i];
    int ny = y + dy[i];

    if (nx >= 0 && nx < R && ny >= 0 && ny < C && arr[nx][ny] < arr[x][y]) {
        int length = 1 + dfs(nx, ny);
        max_length = max(max_length, length);
    }
}

dp[x][y] = max_length;
return max_length;

}

int findLongestPath() {
int max_length = 0;

for (int i = 0; i < R; i++) {
    for (int j = 0; j < C; j++) {
        int length = dfs(i, j);
        max_length = max(max_length, length);
    }
}

return max_length;

}

int main() {
cin >> R >> C;

for (int i = 0; i < R; i++) {
    for (int j = 0; j < C; j++) {
        cin >> arr[i][j];
    }
}

int result = findLongestPath();
cout << result << endl;

return 0;

}