poj 2155 二维树状数组 二维线段树

本文介绍了一种使用二维树状数组和线段树解决矩阵操作问题的方法,包括矩阵元素的翻转和查询操作。通过具体的编程实现展示了如何高效地处理这类问题。

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

二维树状数组。两个for循环就好

#include <cstdio>
#include <string>
#include <cstring>
#include <iostream>
#include <vector>
#define lowbit(x) ((x)&(-x))
using namespace std;
const int maxn=1010;
int c[maxn][maxn];
int n;
void update(int x,int y)
{
    int i,k;
    for(i=x;i<=n;i+=lowbit(i))
    {
        for(k=y;k<=n;k+=lowbit(k))
            c[i][k]++;
    }
}
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 t;
    int x1,x2,y1,y2;
     scanf("%d",&t);
        int m;
        while(t--)
        {
            memset(c,0,sizeof(c));
            scanf("%d%d",&n,&m);
            while(m--)
            {
                char ch;
                scanf(" %c",&ch);
                if(ch=='C') 
                {
                    scanf("%d%d%d%d",&x1,&y1,&x2,&y2);
                    x1++,x2++,y1++,y2++;  //因为更新的时候下面的坐标有的减一所以得从二开始
                    update(x2,y2);
                    update(x1-1,y1-1); 
                    update(x1-1,y2);
                    update(x2,y1-1);

                }
                else
                {
                    scanf("%d%d",&x1,&y1);
                    printf("%d\n",Get(x1,y1)%2);
                }
            }
            printf("\n");
        }

}
#include <iostream>
#include <cstdio>
#include <cstring>
using namespace std;
#define xlson kx<<1,xl,mid
#define xrson kx<<1|1,mid+1,xr
#define ylson ky<<1,yl,mid
#define yrson ky<<1|1,mid+1,yr
#define MAXN 1005
#define mem(a) memset(a,0,sizeof(a));
bool tree[MAXN<<2][MAXN<<2];
int X,N,T;
int num,X1,X2,Y1,Y2;
char ch;
void editY(int kx,int ky,int yl,int yr)
{
    if(Y1<=yl&&yr<=Y2)
    {
        tree[kx][ky]=!tree[kx][ky];
        return ;
    }
    int mid=(yl+yr)>>1;
    if(Y1<=mid) editY(kx,ylson);
    if(Y2>mid) editY(kx,yrson);
}

void editX(int kx,int xl,int xr)
{
    if(X1<=xl&&xr<=X2)
    {
        editY(kx,1,1,N);
        return ;
    }
    int mid=(xl+xr)>>1;
    if(X1<=mid) editX(xlson);
    if(X2>mid) editX(xrson);
}

void queryY(int kx,int ky,int yl,int yr)
{
    if(tree[kx][ky]) num++;//总的全部面积有没有被翻过,就是父区间是否被翻过,先统计父区间
                      //再统计子区间。
    if(yl==yr) return ;
    int mid=(yl+yr)>>1;
    if(Y1<=mid) queryY(kx,ylson);
    else queryY(kx,yrson);
}

void queryX(int kx,int xl,int xr){
        queryY(kx,1,1,N);
        if(xl==xr) return ;
        int mid=(xl+xr)>>1;
        if(X1<=mid) queryX(xlson);
        else queryX(xrson);
}
int main()
{
    int t;
    while(~scanf("%d",&t))
    while(t--)
    {
        scanf("%d%d",&N,&T);
        mem(tree);
        for(int i=0;i<T;i++)
        {
            scanf(" %c%d%d",&ch,&X1,&Y1);
            if(ch=='C') 
            {
                scanf("%d%d",&X2,&Y2);
                editX(1,1,N);
            }
            else
            {
                num=0;
                queryX(1,1,N);
                if(num&1) printf("1\n");
                else printf("0\n");
            }
        }
        if(t) printf("\n"); 
    }

}
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