bzoj1102: [POI2007]山峰和山谷Grz

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>
#define maxn 1005
using namespace std;

int n,sumx,sumy,ansx,ansy,hi[maxn][maxn],list[maxn*maxn][2],head,tail;
bool vis[maxn][maxn];
const int dx[8]={-1,0,1,-1,1,-1,0,1};
const int dy[8]={-1,-1,-1,0,0,1,1,1};
void init(int x){
    for (int i=1;i<=x;i++){
        for (int j=1;j<=x;j++){
            scanf("%d",&hi[i][j]);
        }
    }
}
void bfs(int x,int y){
    int a,b,c,d;
    head=0,tail=1,list[tail][0]=x,list[tail][1]=y; sumx=sumy=0,vis[x][y]=1;
    while (head<tail){
        ++head,a=list[head][0],b=list[head][1];
        for (int i=0;i<8;i++){
            c=a+dx[i],d=b+dy[i];
            if (c>=1&&c<=n&&d>=1&&d<=n){
                if (hi[c][d]==hi[a][b]&&!vis[c][d]){
                    vis[c][d]=1;
                    list[++tail][0]=c,list[tail][1]=d;
                }else{
                    if (hi[c][d]>hi[a][b]) sumx++;
                    if (hi[c][d]<hi[a][b]) sumy++;
                }
            }
        }
    }
//    printf("%d %d %d %d
",x,y,sumx,sumy);
    if (sumx==0&&sumy==0) ansx++,ansy++;
    else if (sumx>0&&sumy>0) return;
    else if (sumx>0) ansy++;
    else ansx++;
}
int main(){
    scanf("%d",&n);
    init(n);
    memset(vis,0,sizeof(vis));
    ansx=ansy=0;
    for (int i=1;i<=n;i++){
        for (int j=1;j<=n;j++){
            if (vis[i][j]==1) continue;
            bfs(i,j);
        }
    }
    printf("%d %d
",ansx,ansy);
    return 0;
}

题目链接：http://www.lydsy.com/JudgeOnline/problem.php?id=1102

做法：为noip做准备。bfs即可。