补充：记忆化搜索不断地改，结果越改越离谱，甚至几万的大数据也出来了
by Ch35 @ 2022-08-15 21:26:05
@[Ch35](/user/672360) 还在吗
by SunRises @ 2022-08-15 21:40:38
真·几个月
by HarryKane @ 2022-08-15 21:41:29
@[SunRises](/user/773197) 还在
by Ch35 @ 2022-08-15 21:44:14
```cpp
#include<bits/stdc++.h>
using namespace std;
int n,m,a[110][110],ans=-1,dp[110][110],nx[5]={0,-1,0,0,1},ny[5]={0,0,-1,1,0};
int dfs(int x,int y){
if(dp[x][y]) return dp[x][y];
dp[x][y]=1;
int next_x,next_y;
for(int i=1;i<=4;i++){
next_x=x+nx[i];
next_y=y+ny[i];
if(next_x>0&&next_x<=n&&next_y>0&&next_y<=m&&a[x][y]>a[next_x][next_y]) dp[x][y]=max(dp[x]
[y],dfs(next_x,next_y)+1);
}
return dp[x][y];
}
int main(){
cin>>n>>m;
for(int i=1;i<=n;i++){
for(int j=1;j<=m;j++){
cin>>a[i][j];
}
}
for(int i=1;i<=n;i++){
for(int j=1;j<=m;j++){
ans=max(ans,dfs(i,j));
}
}
cout<<ans;
return 0;
}
```
by SunRises @ 2022-08-15 21:44:51
```cpp
#include <bits/stdc++.h>
#define reg register
#define inl inline
using namespace std;
int R, C, ans;
int arr[110][110], dp[110][110];
inl int dfs(int x, int y) {
if (x <= 0 || y <= 0 || x > R || y > C) return 0;
if (dp[x][y]) return dp[x][y];
int k = 0;
if (arr[x][y-1] < arr[x][y]) dp[x][y] = max(dp[x][y], dfs(x, y-1));
if (arr[x-1][y] < arr[x][y]) dp[x][y] = max(dp[x][y], dfs(x-1, y));
if (arr[x+1][y] < arr[x][y]) dp[x][y] = max(dp[x][y], dfs(x+1, y));
if (arr[x][y+1] < arr[x][y]) dp[x][y] = max(dp[x][y], dfs(x, y+1));
dp[x][y]++;
return dp[x][y];
}
int main() {
cin >> R >> C;
for (reg int i = 1; i <= R; i++) {
for (reg int j = 1; j <= C; j++) {
cin >> arr[i][j];
}
}
for (reg int i = 1; i <= R; i++) {
for (reg int j = 1; j <= C; j++) {
ans = max(ans, dfs(i, j));
}
}
cout << ans << endl;
return 0;
}
```
by 0x3F @ 2022-08-15 21:51:04
@[Ch35](/user/672360) cnt 没必要啊dp数组里存放的应该就是一个点能到达最远的路径长度啊
by SunRises @ 2022-08-15 21:54:20
@[Ch35](/user/672360) 思路好像有点乱 建议重构吧
by SunRises @ 2022-08-15 21:56:20
@[Ch35](/user/672360) 在下一步DFS前已经更新了下一步位置的dp数组
```cpp
dp[x-1][y]++;
dp[x][y-1]++;
dp[x][y+1]++;
dp[x+1][y]++;
```
下一步DFS就会直接进入if(dp[x][y]!=0)
by SunRises @ 2022-08-15 22:06:49
@[SunRises](/user/773197) @[0x3F](/user/153422) 我AC了，谢谢你们的帮助，我要休息了，早点睡。
by Ch35 @ 2022-08-15 22:09:39