第二个点t了。。。

#include<iostream>
#include<cstdio>
#include<cstring>
using namespace std;
int r,c,a[100][100],dir[4][2]={1,0,-1,0,0,1,0,-1},team[500000][3];
//bool visit[100][100];
int bfs(int x,int y){
    int head=0,tail=0,maxn=1;
    team[0][0]=x;team[0][1]=y;team[0][2]=1;
    while(head<=tail){
        for(int i=0;i<4;i++){
            int kx=team[head][0],ky=team[head][1];
            int dx=team[head][0]+dir[i][0],dy=team[head][1]+dir[i][1];
            if(dx>=0&&dx<r&&dy>=0&&dy<c&&a[kx][ky]>a[dx][dy]){
                tail++;
//                visit[dx][dy]=1;
                team[tail][0]=dx;
                team[tail][1]=dy;
                team[tail][2]=team[head][2]+1;
                if(team[tail][2]>maxn)maxn=team[tail][2];
            }
        }
        head++;
    }
    return maxn;
}
int main(){
    int e,maxx=0;
    cin>>r>>c;
    for(int i=0;i<r;i++){
        for(int h=0;h<c;h++){
            cin>>a[i][h];
        }
    }
    for(int i=0;i<r;i++){
        for(int h=0;h<c;h++){
            e=bfs(i,h);
            if(e>maxx)maxx=e;
//            memset(visit,0,sizeof(visit));
        }
    }
    cout<<maxx;
}