POJ 2155 二维线段树 书套树
2012-04-23 08:32 javaspring 阅读(156) 评论(0) 编辑 收藏 举报是一道裸的二维线段树题目,二维线段树可以用树套树的方式实现。。。。题目:
Matrix
Time Limit: 3000MS | Memory Limit: 65536K | |
Total Submissions: 11798 | Accepted: 4466 |
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].
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.
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.
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 1ac代码:
#include <iostream> #include <cstdio> #include <string.h> using namespace std; const int N=1010; int n,m,ans; struct newtree{ int left,right,value; int getnewmid(){ return (left+right)/2; } }; struct tree{ int left,right; newtree newtt[4*N]; int getmid(){ return (left+right)/2; } }tt[4*N]; void built_treey(int lp,int rp,int posx,int posy){ tt[posx].newtt[posy].left=lp; tt[posx].newtt[posy].right=rp; tt[posx].newtt[posy].value=0; if(lp==rp)return; int mid=tt[posx].newtt[posy].getnewmid(); built_treey(lp,mid,posx,posy*2); built_treey(mid+1,rp,posx,posy*2+1); } void built_treex(int lp,int rp,int pos){ tt[pos].left=lp; tt[pos].right=rp; built_treey(1,n,pos,1); if(lp==rp)return; int mid=tt[pos].getmid(); built_treex(lp,mid,pos*2); built_treex(mid+1,rp,pos*2+1); } void update_y(int y1,int y2,int posx,int posy){ if(tt[posx].newtt[posy].left==y1&&tt[posx].newtt[posy].right==y2){ tt[posx].newtt[posy].value=!tt[posx].newtt[posy].value; return; } int mid=tt[posx].newtt[posy].getnewmid(); if(y2<=mid) update_y(y1,y2,posx,posy*2); else if(y1>mid) update_y(y1,y2,posx,posy*2+1); else{ update_y(y1,mid,posx,posy*2); update_y(mid+1,y2,posx,posy*2+1); } } void update_x(int x1,int x2,int y1,int y2,int pos){ if(tt[pos].left==x1&&tt[pos].right==x2){ update_y(y1,y2,pos,1); return; } int mid=tt[pos].getmid(); if(x2<=mid) update_x(x1,x2,y1,y2,pos*2); else if(x1>mid) update_x(x1,x2,y1,y2,pos*2+1); else{ update_x(x1,mid,y1,y2,pos*2); update_x(mid+1,x2,y1,y2,pos*2+1); } } void find_y(int y,int posx,int posy){ ans^=tt[posx].newtt[posy].value; if(tt[posx].newtt[posy].left==tt[posx].newtt[posy].right) return; int mid=tt[posx].newtt[posy].getnewmid(); if(y>mid) find_y(y,posx,posy*2+1); else find_y(y,posx,posy*2); } void find_x(int x,int y,int pos){ find_y(y,pos,1); if(tt[pos].left==tt[pos].right) return; int mid=tt[pos].getmid(); if(x>mid) find_x(x,y,pos*2+1); else find_x(x,y,pos*2); } int main(){ //freopen("1.txt","r",stdin); int numcase; scanf("%d",&numcase); while(numcase--){ scanf("%d%d",&n,&m); built_treex(1,n,1); char ss[2]; int x1,x2,y1,y2,x,y; while(m--){ scanf("%s",ss); if(ss[0]=='C'){ scanf("%d%d%d%d",&x1,&y1,&x2,&y2); update_x(x1,x2,y1,y2,1); } else{ scanf("%d%d",&x,&y); ans=0; find_x(x,y,1); printf("%d\n",ans); } } puts(""); } return 0; }