Matrix
Time Limit: 3000MS | Memory Limit: 65536K | |
Total Submissions: 19174 | Accepted: 7207 |
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 Note 这是一个二维的树状数组,区间更新,单点查询
#include <queue> #include <stack> #include <math.h> #include <stdio.h> #include <stdlib.h> #include <iostream> #include <limits.h> #include <string.h> #include <algorithm> using namespace std; const int MAX = 1010; int c[MAX][MAX]; int n; int a,b,e,d; int Lowbit(int x) { return x & (-x); } void Updata(int x,int y,int z) { int i,k; for(i=x; i<=n; i+=Lowbit(i)) for(k=y; k<=n; k+=Lowbit(k)) c[i][k]+=z; } int Get(int x,int y) { int i,k,sum = 0; for(i=x; i>0; i-=Lowbit(i)) for(k=y; k>0; k-=Lowbit(k)) sum += c[i][k]; return sum; } int main() { int x; scanf("%d",&x); while(x--) { memset(c,0,sizeof(c)); int q; scanf("%d%d",&n,&q); char s; while(q--) { //cout<<q<<endl; scanf(" %c",&s); if(s==‘C‘) { scanf("%d%d%d%d",&a,&b,&e,&d); a++,b++,e++,d++; Updata(e,d,1); Updata(a-1,d,-1); Updata(e,b-1,-1); Updata(a-1,b-1,1); } if(s==‘Q‘) { scanf("%d%d",&a,&b); printf("%d\n",Get(a,b)%2); } } if(x!=0) printf("\n"); } return 0; }