UVa-806 Spatial Structures(四分树)

代码借鉴：http://www.cnblogs.com/npugen/p/9527453.html

#include <bits/stdc++.h>
#define _for(i,a,b) for(int i = (a);i < (b);i ++)
using namespace std;
//1 2
//3 4

const int maxn = 70;
int n,cnt;
char gra[maxn][maxn];
vector<int> ans;
vector<int> num;

bool is_black(int r,int c,int wide)
{
    _for(i,r,r+wide)
        _for(j,c,c+wide)
            if(gra[i][j] == '0') return false;
    return true;
}

bool is_white(int r,int c,int wide)
{
    _for(i,r,r+wide)
        _for(j,c,c+wide)
            if(gra[i][j] == '1') return false;
    return true;
}

int consumption(string &ss)
{
    int res = 0;
    for(int i = ss.size()-1;i >= 0;i --)
    {
        res *= 5;
        res += ss[i]-'0';
    }
    return res;
}

void cal(string str,int r,int c,int wide)
{
    if(is_black(r,c,wide))
    {
        ans.push_back(consumption(str));
    }
    else if(is_white(r,c,wide))    
        ;
    else
    {
        cal(str+"1",r,c,wide/2);
        cal(str+"2",r,c+wide/2,wide/2);
        cal(str+"3",r+wide/2,c,wide/2);
        cal(str+"4",r+wide/2,c+wide/2,wide/2);
    }
}

int solve(int n)
{
    cnt = 0;
    ans.clear();
    memset(gra,0,sizeof(gra));
    _for(i,0,n)    scanf("%s",gra[i]);
    string str = "";
    if(is_black(0,0,n))    return 1;
    if(is_white(0,0,n)) return -1;
    cal(str+"1",0,0,n/2);
    cal(str+"2",0,n/2,n/2);
    cal(str+"3",n/2,0,n/2);
    cal(str+"4",n/2,n/2,n/2);
    return 0;
}

void converse(int val,string &ss)
{
    while(val)
    {
        ss += (val%5+'0');
        val /= 5;
    }
}

void draw(string &ss,int pos,int r,int c,int wide)
{
    if(pos == ss.size())
    {
        _for(i,r,r+wide)
            _for(j,c,c+wide)
                gra[i][j] = '*';
        return ;
    }
    if(ss[pos] == '1')
        draw(ss,pos+1,r,c,wide/2);
    else if(ss[pos] == '2')
        draw(ss,pos+1,r,c+wide/2,wide/2);
    else if(ss[pos] == '3')
        draw(ss,pos+1,r+wide/2,c,wide/2);
    else if(ss[pos] == '4')
        draw(ss,pos+1,r+wide/2,c+wide/2,wide/2);
}

void solve2(int n)
{
    int x;
    num.clear();
    memset(gra,0,sizeof(gra));
    while(scanf("%d",&x) && x!=-1) num.push_back(x);
    if(num.size()==1 && num[0]==0)
    {
        _for(i,0,n)
        {
            _for(j,0,n)
            {
                cout << "*";
            }
            cout << endl;
        }
        return ;
    }
    _for(i,0,num.size())
    {
        string ss = "";
        converse(num[i],ss);
        draw(ss,0,0,0,n);
    }

    _for(i,0,n)
    {
        _for(j,0,n)
        {
            if(gra[i][j]== '*')    cout << gra[i][j];
            else cout << ".";
        }
        cout << endl;
    }
}

int iCase = 1;

int main()
{
    bool flag = false;
    while(~scanf("%d",&n) && n)
    {
        if(flag) cout << endl;
        flag = true;
        if(n > 0)
        {
            int flag = solve(n);
            printf("Image %d
",iCase ++);
            if(flag == 1)
            {
                printf("%d
",0);
                printf("Total number of black nodes = %d
",1);
            }
            else if(flag == -1)
            {
                printf("Total number of black nodes = %d
",0);
            }
            else
            {
                sort(ans.begin(),ans.end());
                int cnt = 0;
                _for(i,0,ans.size())
                {
                    if(cnt == 0) printf("%d",ans[i]);
                    else printf(" %d",ans[i]);
                    cnt ++;
                    if(cnt == 12) cnt = 0,printf("
");
                }
                if(ans.size()%12) printf("
");
                printf("Total number of black nodes = %d
",ans.size());
            }
        }
        else
        {
            printf("Image %d
",iCase ++);
            solve2(-n);
        }
    }
    return 0;
}