40分WA

#include<iostream>
using namespace std;
short R,C,a[101][101],xx[5]={0,1,-1,0,0},yy[5]={0,0,0,-1,1};
int f[101][101],ans,ansn=1;
void dfs(short x,short y,int ans1){
    if(f[x][y]!=0){
        ans1+=f[x][y];
        ansn=max(ansn,ans1);
        return;
    }
    for(int i=1;i<=4;i++){
        if(x+xx[i]<=R&&x+xx[i]>=1&&y+yy[i]<=C&&y+yy[i]>=1&&a[x+xx[i]][y+yy[i]]<a[x][y]){
            ans1++;
            dfs(x+xx[i],y+yy[i],ans1);
            ans1--;
        }
        else{
            if(i==4){
                ansn=max(ansn,ans1);
                f[x][y]=ansn;
                return;
            }
        }
    }
}
int main(){
    cin>>R>>C;
    for(short i=1;i<=R;i++){
        for(short j=1;j<=C;j++){
            cin>>a[i][j];
        }
    }
    for(short i=1;i<=R;i++){
        for(short j=1;j<=C;j++){
            dfs(i,j,ansn);
            ans=max(ans,ansn);
            ansn=0;
        }
    }
    cout<<ans<<endl;
    return 0;
}

40分，样例过了