第5个点和第7个点wa了

思路是从高度最小的点开始

每一个点的步数为它周围四格点的最大步数加一

不知道哪里有问题...恳请奆犇指点！

#include<bits/stdc++.h>
using namespace std;
struct T{
	int high,step;
}mapp[1007][1007];
struct Y{
	int x,y,highh;
}sor[1000007];
bool Cmp(Y a,Y b){
	return a.highh<b.highh;
}
int find(int xx,int yy){
	int ax[5],ay[5],hmy=0;
	if(mapp[xx-1][yy].high<mapp[xx][yy].high&&mapp[xx-1][yy].high!=0){
		hmy++;
		ax[hmy]=xx-1;
		ay[hmy]=yy;
	}
	if(mapp[xx+1][yy].high<mapp[xx][yy].high&&mapp[xx+1][yy].high!=0){
		hmy++;
		ax[hmy]=xx+1;
		ay[hmy]=yy;
	}
	if(mapp[xx][yy+1].high<mapp[xx][yy].high&&mapp[xx][yy+1].high!=0){
		hmy++;
		ax[hmy]=xx;
		ay[hmy]=yy+1;
	}
	if(mapp[xx][yy-1].high<mapp[xx][yy].high&&mapp[xx][yy-1].high!=0){
		hmy++;
		ax[hmy]=xx;
		ay[hmy]=yy-1;
	}
	if(hmy==0)return mapp[xx][yy].step=1;
	if(hmy==1)return mapp[xx][yy].step=mapp[ax[1]][ay[1]].step+1;
	if(hmy==2)return mapp[xx][yy].step=max(mapp[ax[1]][ay[1]].step+1,mapp[ax[2]][ay[2]].step+1);
	if(hmy==3)return mapp[xx][yy].step=max(mapp[ax[3]][ay[3]].step+1,max(mapp[ax[1]][ay[1]].step+1,mapp[ax[2]][ay[2]].step+1));
	if(hmy==4)return mapp[xx][yy].step=max(mapp[ax[4]][ay[4]].step+1,max(mapp[ax[3]][ay[3]].step+1,max(mapp[ax[1]][ay[1]].step+1,mapp[ax[2]][ay[2]].step+1)));
}
int now,ans=0;
int main(){
	int nx,ny;
	cin>>nx>>ny;
	for(int i=1;i<=nx;i++){
		for(int j=1;j<=ny;j++){
			scanf("%d",&mapp[i][j].high);
			mapp[i][j].step=1;
			sor[++now].x=i;
			sor[now].y=j;
			sor[now].highh=mapp[i][j].high;
		}
	}
	sort(sor+1,sor+now+1,Cmp);
	for(int i=1;i<=now;i++){
		ans=max(ans,find(sor[i].x,sor[i].y));
	}
	cout<<ans;
	return 0;
}