【坐标离散化】AOJ0531- Paint Color

日文题……一开始被题目骗了以为真的要写文件？

题目大意&&解答戳：❀

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cstdlib>
#include<algorithm>
#include<vector>
#include<queue>
using namespace std;
int w,h,n,ans;
const int MAXN=1000+10;
int x1[MAXN],x2[MAXN],y1[MAXN],y2[MAXN];
int hashx[MAXN*2],hashy[MAXN*2];
int fld[MAXN*2][MAXN*2]; 
int dx[4]={0,0,1,-1};
int dy[4]={1,-1,0,0};

void compress()
{
    int tx=0,ty=0;
    for (int i=1;i<=n;i++)
    {
        hashx[++tx]=x1[i];hashx[++tx]=x2[i];
        hashy[++ty]=y1[i];hashy[++ty]=y2[i];
    }
    hashx[++tx]=0;hashx[++tx]=w;
    hashy[++ty]=0;hashy[++ty]=h;
    sort(hashx+1,hashx+tx+1);
    sort(hashy+1,hashy+ty+1);
    w=unique(hashx+1,hashx+tx+1)-(hashx+1);
    h=unique(hashy+1,hashy+ty+1)-(hashy+1);
    for (int i=1;i<=n;i++)
    {
        x1[i]=lower_bound(hashx+1,hashx+w+1,x1[i])-hashx-1;
        x2[i]=lower_bound(hashx+1,hashx+w+1,x2[i])-hashx-1;
        y1[i]=lower_bound(hashy+1,hashy+h+1,y1[i])-hashy-1;
        y2[i]=lower_bound(hashy+1,hashy+h+1,y2[i])-hashy-1;
    }
    w--;h--;
}

void init()
{
    scanf("%d",&n);
    for (int i=1;i<=n;i++)
        scanf("%d%d%d%d",&x1[i],&y1[i],&x2[i],&y2[i]);
    compress();
}

void imos()    /*imos?*/
{
    memset(fld,0,sizeof(fld));
    for (int i=1;i<=n;i++)
    {
        fld[x1[i]][y1[i]]++;
        fld[x2[i]][y2[i]]++;
        fld[x1[i]][y2[i]]--;
        fld[x2[i]][y1[i]]--;
    }
    
    for (int i=0;i<w;i++)
        for (int j=1;j<h;j++)
            fld[i][j]+=fld[i][j-1];
            
    for (int j=0;j<h;j++)
        for (int i=1;i<w;i++)
            fld[i][j]+=fld[i-1][j];
}

void bfs(int x,int y)
{
    ans++;
    queue<int> qx,qy;
    qx.push(x);
    qy.push(y);
    fld[x][y]=1;
    while (!qx.empty())
    {
        int xx=qx.front();qx.pop();
        int yy=qy.front();qy.pop();
        for (int i=0;i<4;i++)
        {
             int nx=xx+dx[i],ny=yy+dy[i];
             if (nx<0 || ny<0 || nx>w || ny>h || fld[nx][ny]>0) continue;
             qx.push(nx);
             qy.push(ny);
             fld[nx][ny]=1;
        }
    }
}

void solve()
{
    ans=0;
    for (int i=0;i<w;i++)
        for (int j=0;j<h;j++)
            if (fld[i][j]==0) bfs(i,j);
    printf("%d
",ans);
}

int main()
{
    //freopen("input.txt","r",stdin);
    //freopen("output.txt","w",stdout);
    while (~scanf("%d%d",&w,&h)&&w&&h)
    {
        init();
        imos();
        solve();
    }
    return 0;    
}