第二个点TLE，90分求助

#include<iostream>
#include<algorithm>
#include<cstring>
#include<cstdio>
#include<cmath>
#include<iomanip>
using namespace std;
int j,k,map[105][105],maxx=0,xz[5]={0,0,0,-1,1},yz[5]={0,1,-1,0,0};
int dfs(int x,int y){
    int flag=0,ma1=0,ma2=0;
    for(int v=1;v<=4;v++){
        if(x+xz[v]>=1&&x+xz[v]<=j&&y+yz[v]>=1&&y+yz[v]<=k&&map[x][y]>map[x+xz[v]][y+yz[v]]){
            flag=1;
            ma1=dfs(x+xz[v],y+yz[v]);
            if(ma1>ma2){
                ma2=ma1;
            }
        }
    }
    if(!flag){
        return 1;
    }else{
        return ma2+1;
    }
}
int main(){
    cin>>j>>k;
    for(int m=1;m<=j;m++){
        for(int n=1;n<=k;n++){
            cin>>map[m][n];
        }
    }
    for(int m=1;m<=j;m++){
        for(int n=1;n<=k;n++){
            int a=dfs(m,n);
            if(a>maxx){
                maxx=a;
            }
        }
    }
    cout<<maxx;
}