救救蒟蒻吧，此蒟蒻打了优化都TLE啊！

#include<bits/stdc++.h>
using namespace std;
int mp[1001][1001],n,m,f[1001][1001];
inline int max(int x,int y){return x>y?x:y;}
inline int read(){
    register int x=0;
    register char c=getchar();
    while(c<'0'||c>'9')c=getchar();
    while(c>='0'&&c<='9')x=(x<<1)+(x<<3)+(c^48),c=getchar();
    return x;
}
inline void write(int x){
    if(x<0)x=-x,putchar(45);
    if(x)write(x/10);
    else return ;
    putchar(x%10+48);
    return ;
}
inline int dfs(register int x,register int y){
    if(f[x][y]!=1)return f[x][y];
    int res=0;
    if(x+1<=n&&mp[x+1][y]<mp[x][y])res=max(res,dfs(x+1,y)+1);
    if(x-1>=1&&mp[x-1][y]<mp[x][y])res=max(res,dfs(x-1,y)+1);
    if(y+1<=m&&mp[x][y+1]<mp[x][y])res=max(res,dfs(x,y+1)+1);
    if(y-1>=1&&mp[x][y-1]<mp[x][y])res=max(res,dfs(x,y-1)+1);
    return max(f[x][y],res);
}
int main(){
    n=read();m=read();
    for(register int i=1;i<=n;i++){
        for(register int j=1;j<=m;j++)
        mp[i][j]=read(),f[i][j]=1;
    }
    register int ans=0;
    for(register int i=1;i<=n;i++){
        for(register int j=1;j<=m;j++)
        ans=max(ans,dfs(i,j));
    }
    write(ans);
    return 0;
}

大佬不要氧气