POJ 2155 Matrix

#include<iostream>
#include<cstdio>
#include<cmath>
#include<cstring>
#include<sstream>
#include<algorithm>
#include<queue>
#include<deque>
#include<iomanip>
#include<vector>
#include<cmath>
#include<map>
#include<stack>
#include<set>
#include<fstream>
#include<memory>
#include<list>
#include<string>
using namespace std;
typedef long long LL;
typedef unsigned long long ULL;
#define MAXN 1000 + 23
#define L 31
#define INF 1000000009
#define eps 0.00000001
#define sf(a) scanf("%d",&a)
int T, n, k;
int a[MAXN][MAXN];
char op[2];
inline int lowbit(int x)
{
    return x&(-x);
}
void update(int x, int y)
{
    for (int i = x; i < MAXN; i += lowbit(i) )
    {
        for (int j = y; j < MAXN; j += lowbit(j) )
        {
            a[i][j]++;
        }
    }
}

int query(int x, int y)
{
    int sum = 0;
    for (int i = x; i > 0; i -= lowbit(i))
    {
        for (int j = y; j > 0; j -= lowbit(j))
        {
            sum += a[i][j];
        }
    }
    return sum;
}
int main()
{
    int x1, y1, x2, y2;
    sf(T);
    while (T--)
    {
        memset(a, 0, sizeof(a));
        sf(n), sf(k);
        for (int i = 0; i < k; i++)
        {
            scanf("%s", op);
            if (op[0] == 'C')
            {
                sf(x1), sf(y1), sf(x2), sf(y2);
                x1++, y1++, x2++, y2++;//避免出现0

                update(x1, y1);
                update(x1, y2 + 1);
                update(x2 + 1, y1);
                update(x2 + 1, y2 + 1);//重叠的部分加上 
            }
            else
            {
                sf(x1), sf(y1);
                x1++, y1++;
                printf("%d\n", query(x1, y1) % 2);
            }
        }
        cout << endl;
    }
}