Counting Black
There is a board with 100 * 100 grids as shown below. The left-top gird is denoted as (1, 1) and the right-bottom grid is (100, 100).
We may apply three commands to the board:
1. WHITE x, y, L // Paint a white square on the board, // the square is defined by left-top grid (x, y) // and right-bottom grid (x+L-1, y+L-1) 2. BLACK x, y, L // Paint a black square on the board, // the square is defined by left-top grid (x, y) // and right-bottom grid (x+L-1, y+L-1) 3. TEST x, y, L // Ask for the number of black grids // in the square (x, y)- (x+L-1, y+L-1)
In the beginning, all the grids on the board are white. We apply a series of commands to the board. Your task is to write a program to give the numbers of black grids within a required region when a TEST command is applied.
Input
The first line of the input is an integer t (1 <= t <= 100), representing the number of commands. In each of the following lines, there is a command. Assume all the commands are legal which means that they won't try to paint/test the grids outside the board.
Output
For each TEST command, print a line with the number of black grids in the required region.
Sample Input
5 BLACK 1 1 2 BLACK 2 2 2 TEST 1 1 3 WHITE 2 1 1 TEST 1 1 3
Sample Output
7 6
C++版本一
#include <iostream>
#include <stdio.h>
#include <algorithm>
#include <string.h>
#include <math.h>
int X,n,t;
using namespace std;
const int N=110;
int tree[N][N],color[N][N];
void init(){
for(int i=1;i<=100;i++)
for(int j=1;j<=100;j++)
tree[i][j]=0;
}
int lowbit(int x){
return x&(-x);
}
void updata(int x, int y, int c)
{
int i, j;
int val=0;
if(color[x][y] == c)
return;
if(c == 1) val = 1;
else if(color[x][y] == 1)
val = -1;
color[x][y] = c;
if(val == 0)
return;
for(i = x; i <= 100; i += lowbit(i))
for(j = y; j <= 100; j += lowbit(j))
tree[i][j] += val;
}
int query(int x,int y){
int res=0;
for(int i=x;i>0;i-=lowbit(i))
for(int j=y;j>0;j-=lowbit(j))
res+=tree[i][j];
return res;
}
int main()
{
scanf("%d",&n);
init();
char tmp[10];
int x,y,l;
while(n--){
scanf("%s",tmp);
scanf("%d%d%d",&x,&y,&l);
if(tmp[0]=='W'){
for(int i = x; i < x + l; i++)
for(int j = y; j < y + l; j++)
updata(i,j,0);
}else if(tmp[0]=='B'){
for(int i = x; i < x + l; i++)
for(int j = y; j < y + l; j++)
updata(i,j,1);
}else{
printf("%d\n",query(x+l-1,y+l-1)+query(x-1,y-1)-query(x+l-1,y-1)-query(x-1,y+l-1) );
//cout << query(x,y) << endl;
}
}
//cout << "Hello world!" << endl;
return 0;
}
C++版本二
#include <iostream>
#define MAXNUM 101
using namespace std;
int point[MAXNUM][MAXNUM];//标记格子颜色
int main()
{
int t;//t种情况
//(x y)左上坐标 (x1,y1)右下坐标 num:记录黑色数目
int x,y,x1,y1,l,num;
string s;//命令cmd
cin>>t;//命令数目
while(t--)
{
num = 0;
cin>>s>>x>>y>>l;
x1 = x+l-1;
y1 = y+l-1;
//黑色命令,把区域内的块设置为黑色:1
if(s.compare("BLACK")==0)
{
for(int i = x; i <= x1; ++i)
for(int j = y; j <= y1; ++j)
{
point[i][j] = 1;
}
}
//白色命令,把区域内的块设置为白色:0
else if(s.compare("WHITE")==0)
{
for(int i = x; i <= x1; ++i)
for(int j = y; j <= y1; ++j)
{
point[i][j] = 0;
}
}
//测试命令,输出黑色块的数目
else if(s.compare("TEST")==0)
{
for(int i = x; i <= x1; ++i)
for(int j = y; j <= y1; ++j)
{
if(point[i][j]==1)num++;
}
cout<<num<<endl;
}
}
return 0;
}