标签：des blog io os ar for sp div 2014
Matrix
Description
Given an N*N matrix A, whose elements are either 0 or 1. A[i, j] means the number in the i-th row and j-th column. Initially we have A[i, j] = 0 (1 <= i, j <= N).
We can change the matrix in the following way. Given a rectangle whose upper-left corner is (x1, y1) and lower-right corner is (x2, y2), we change all the elements in the rectangle by using "not" operation (if it is a ‘0‘ then change it into ‘1‘ otherwise change
it into ‘0‘). To maintain the information of the matrix, you are asked to write a program to receive and execute two kinds of instructions.
1. C x1 y1 x2 y2 (1 <= x1 <= x2 <= n, 1 <= y1 <= y2 <= n) changes the matrix by using the rectangle whose upper-left corner is (x1, y1) and lower-right corner is (x2, y2).
2. Q x y (1 <= x, y <= n) querys A[x, y].
Input
The first line of the input is an integer X (X <= 10) representing the number of test cases. The following X blocks each represents a test case.
The first line of each block contains two numbers N and T (2 <= N <= 1000, 1 <= T <= 50000) representing the size of the matrix and the number of the instructions. The following T lines each represents an instruction having the format "Q x y" or "C x1 y1 x2
y2", which has been described above.
Output
For each querying output one line, which has an integer representing A[x, y].
There is a blank line between every two continuous test cases.
Sample Input
1
2 10
C 2 1 2 2
Q 2 2
C 2 1 2 1
Q 1 1
C 1 1 2 1
C 1 2 1 2
C 1 1 2 2
Q 1 1
C 1 1 2 1
Q 2 1
Sample Output
1
0
0
1
# include<iostream>
# include<cstdio>
# include<cstring>
# include<string>
# include<set>
# include<map>
# include<sstream>
using namespace std;
const int maxn=1000+5;
int tree[maxn][maxn];
char a[10];
int n;
int lowbit(int x)
{
return x&-x;
}
int getsum(int x,int y)
{
int s=0;
for(int i=x;i>0;i-=lowbit(i))
for(int j=y;j>0;j-=lowbit(j))
s+=tree[i][j];
if(s%2==0) return 0;
else
return 1;
}
void update(int x,int y)
{
for(int i=x;i<=n;i+=lowbit(i))
for(int j=y;j<=n;j+=lowbit(j))
tree[i][j]^=1;
}
int main()
{
/*#ifndef ONLINE_JUDGE
freopen("in.cpp","r",stdin);
freopen("out.cpp","w",stdout);
#endif*/
int t;
scanf("%d",&t);
while(t--)
{
int m;
scanf("%d%d",&n,&m);
for(int i=1; i<=n; i++)
for(int j=1; j<=n; j++)
tree[i][j]=0;
while(m--)
{
int x1,y1,x2,y2;
scanf("%s%d%d",&a[0],&x1,&y1);
if(a[0]=='C')
{
scanf("%d%d",&x2,&y2);
update(x2+1,y2+1);
update(x2+1,y1);
update(x1,y2+1);
update(x1,y1);
}
else if(a[0]=='Q')
{
printf("%d\n",getsum(x1,y1));
}
}
cout<<endl;
}
return 0;
}
Matrix+POJ+二维树状数组初步
标签：des blog io os ar for sp div 2014
原文地址：http://blog.csdn.net/u013514722/article/details/40190455
