棋盘覆盖问题（分治）

#include<iostream>
#include<string>
#include<cstdio>
#include<algorithm>
#include<cstring>
using namespace std;
const int MAXN=105;
int cnt;
int mat[MAXN][MAXN];

void chessBoard(int tr,int tc,int dr,int dc,int sz)
{
int s,t;
if(sz==1) return;
s=sz/2;
t=++cnt;

if(dr<tr+s&&dc<tc+s)
{
chessBoard(tr,tc,dr,dc,s);
}else
{
mat[tr+s-1][tc+s-1]=t;
chessBoard(tr,tc,tr+s-1,tc+s-1,s);
}

if(dr<tr+s&&dc>=tc+s)
{
chessBoard(tr,tc+s,dr,dc,s);
}else
{
mat[tr+s-1][tc+s]=t;
chessBoard(tr,tc+s,tr+s-1,tc+s,s);
}

if(dr>=tr+s&&dc<tc+s)
{
chessBoard(tr+s,tc,dr,dc,s);
}else
{
mat[tr+s][tc+s-1]=t;
chessBoard(tr+s,tc,tr+s,tc+s-1,s);
}

if(dr>=tr+s&&dc>=tc+s)
{
chessBoard(tr+s,tc+s,dr,dc,s);
}else
{
mat[tr+s][tc+s]=t;
chessBoard(tr+s,tc+s,tr+s,tc+s,s);
}
}

int main()
{
int sz;
int dr,dc;
while(cin>>sz)
{
cin>>dr>>dc;
memset(mat,0,sizeof(mat));
chessBoard(0,0,dr,dc,sz);
cnt=0;
for(int i=0;i<sz;i++)
{
for(int j=0;j<sz;j++)
{
printf("%2d ",mat[i][j]);
}
printf("\n");
}
}
return 0;
}