UVA-806 Spatial Structures （四分树）

# include<iostream>
# include<cstdio>
# include<vector>
# include<string>
# include<cstring>
# include<algorithm>
using namespace std;

char p[80][80];
int ans;
vector<int>v;

int get(int r,int c,int w)
{
    int cnt=0;
    for(int i=r;i<r+w;++i)
        for(int j=c;j<c+w;++j)
            if(p[i][j]==‘1‘)
                ++cnt;
    return cnt;
}

int getVal(string path)
{
    int l=path.size();
    int res=0;
    for(int i=l-1;i>=0;--i)
        res=res*5+path[i]-‘0‘;
    return res;
}

///查看以(r,c)为左上角，边长为w的子正方形。下同。
void f1(int r,int c,int w,string path)
{
    int k=get(r,c,w);
    if(k==0)
        return ;
    if(k==w*w){
        ++ans;
        v.push_back(getVal(path));
        return ;
    }
    f1(r,c,w/2,path+‘1‘);
    f1(r,c+w/2,w/2,path+‘2‘);
    f1(r+w/2,c,w/2,path+‘3‘);
    f1(r+w/2,c+w/2,w/2,path+‘4‘);
}

void f2(int r,int c,int w,int s)
{
    if(s==0){
        for(int i=r;i<r+w;++i)
            for(int j=c;j<c+w;++j)
                p[i][j]=‘*‘;
        return ;
    }
    int mod=s%5;
    if(mod==1)
        f2(r,c,w/2,s/5);
    else if(mod==2)
        f2(r,c+w/2,w/2,s/5);
    else if(mod==3)
        f2(r+w/2,c,w/2,s/5);
    else if(mod==4)
        f2(r+w/2,c+w/2,w/2,s/5);
}

int main()
{
    //freopen("UVA-806 Spatial Structures.txt","r",stdin);
    int n,cas=0,flag=0;
    while(scanf("%d",&n)&&n)
    {
        v.clear();
        if(flag)
            printf("\n");
        flag=1;
        if(n>0){
            for(int i=0;i<n;++i)
                scanf("%s",p[i]);
            printf("Image %d\n",++cas);
            ans=0;
            f1(0,0,n,"");
            sort(v.begin(),v.end());
            int l=v.size();
            for(int i=0;i<l;++i)
                printf("%d%c",v[i],(i%12==11||i==l-1)?‘\n‘:‘ ‘);
            printf("Total number of black nodes = %d\n",ans);
        }
        if(n<0){
            n=-n;
            for(int i=0;i<n;++i){
                for(int j=0;j<n;++j)
                    p[i][j]=‘.‘;
                p[i][n]=0;
            }
            int a;
            while(scanf("%d",&a)&&a!=-1)
                v.push_back(a);
            printf("Image %d\n",++cas);
            int l=v.size();
            for(int i=0;i<l;++i)
                f2(0,0,n,v[i]);
            for(int i=0;i<n;++i)
                puts(p[i]);
        }
    }
    return 0;
}