POJ2155 Matrix 二维树状数组
神一般的二维区间更新,运用二维树状数组会有神奇的效果。更改四个角实现区间更改的效果实在是太神奇了。。
#pragma warning(disable:4996)
#include<iostream>
#include<cstdio>
#include<cstring>
#include<algorithm>
#include<vector>
#include<cmath>
#define maxn 1000
using namespace std;
int bit[maxn + 50][maxn + 50];
int n;
void inc(int i, int j,int m)
{
for (; i <= n; i += i&(-i)){
for (int tmpj = j; tmpj <= n; tmpj += (tmpj&(-tmpj)))
bit[i][tmpj] += m;
}
}
int get(int i, int j)
{
int sum = 0;
for (; i > 0; i -= i&-i){
for (int tmpj = j; tmpj > 0; tmpj -= tmpj&-tmpj)
sum += bit[i][tmpj];
}
return sum;
}
int q;
int main()
{
int T; cin >> T;
while (T--)
{
memset(bit, 0, sizeof(bit));
scanf("%d%d", &n, &q);
char str[3]; int x1, y1, x2, y2;
for (int i = 0; i < q; i++)
{
scanf("%s",str);
if (str[0] == 'C'){
scanf("%d%d%d%d", &x1, &y1, &x2, &y2);
x2++; y2++;
inc(x1, y1,1); inc(x2, y2,1); inc(x1, y2,-1); inc(x2, y1,-1);
}
else{
scanf("%d%d", &x1, &y1);
printf("%d\n", get(x1, y1) & 1);
}
}
if (T) puts("");
}
return 0;
}
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