#include<iostream>
#include<algorithm>
using namespace std;

int length,wide,map_high[3002][3002],hd,tl,q[3000002][4],by,nx,ny;
int dx[5]={-1,0,0,1},dy[5]={0,-1,1,0},res[3002][3002],bx,maxx;

void bfs(int x,int y){
	hd=0;tl=1;q[1][0]=x;q[1][1]=y;res[x][y]=1;
	while(hd^tl){
		hd++;int a[5][3]={0};
		for(int i=0;i<4;i++){
			nx=q[hd][0]+dx[i];
			ny=q[hd][1]+dy[i];
			if(nx<1||nx>length||ny<1||ny>wide||res[nx][ny]||map_high[nx][ny]>map_high[q[hd][0]][q[hd][1]])continue;
		    a[i][2]=map_high[nx][ny];a[i][0]=nx;a[i][1]=ny;
		}
		int maxh=a[1][2],cx=a[1][0],cy=a[1][1];
		for(int i=2;i<=4;i++)
		   if(a[i][2]>maxh){maxh=a[i][2];cx=a[i][0];cy=a[i][1];}
		tl++;res[cx][cy]=1;q[tl][0]=maxh;q[tl][1]=cy;q[tl][0]=cx;q[tl][2]=q[hd][2]+1;
		if(maxh==0)return;
	}
}
int main(){
	cin>>length>>wide;
	for(int i=1;i<=length;i++)
	   for(int j=1;j<=wide;j++)
	      cin>>map_high[i][j];
	maxx=map_high[1][1];bx=1;by=1;
	for(int i=1;i<=length;i++)
	   for(int j=1;j<=wide;j++)
	      if(map_high[i][j]>maxx){
	         maxx=map_high[i][j];
	         bx=i;by=j;
		  }
	bfs(bx,by);
	cout<<q[tl][2];
	return 0;
}

• 就这样 (1472) hnzhzs 2019-09-07 15:40:03