巨佬神犇请点击！！！70分求助

1、9两个点WA，2TLE

#include<bits/stdc++.h>
using namespace std;
int n,m;
int h[105][105];
int maxn = -1;
int next[4][2] = {{1,0},{0,1},{-1,0},{0,-1}};

struct Point
{
    int x,y;
    int v;
};
bool cmp(Point a,Point b)
{
    return a.v > b.v;
}

void dfs(int x,int y,int step)
{
    bool flag = false;
    for(int i = 0;i < 4;i++)
    {
        int nx = x + next[i][0],ny = y + next[i][1];
        if(nx > 0 && nx <= n && ny > 0 && ny <= m)
            if(h[nx][ny] < h[x][y])
            {
                flag = true;
                dfs(nx,ny,step+1);
            }
    }
    if(!flag)
        maxn = max(maxn,step);
}

int main()
{
    Point k[10005];
    int topk = 0;
    scanf("%d%d",&n,&m);
    for(int i = 1;i <= n;i++)
        for(int j = 1;j <= m;j++)
        {
            scanf("%d",&h[i][j]);
            Point kkk;
            kkk.v = h[i][j];
            kkk.x = i;
            kkk.y = j;
            k[topk++] = kkk;
        }
    sort(k,k + topk,cmp);
    for(int i = 0;i < topk;i++)
    {
        if(maxn >= n - i)
            break;
        dfs(k[i].x,k[i].y,1);
    }
    cout<<maxn;
    return 0;
}