usaco2008 nov 区间异或求和

Problem 11: Switching Lights [LongFan, 2008]

Farmer John tries to keep the cows sharp by letting them play with
intellectual toys. One of the larger toys is the lights in the barn.
Each of the N (2 <= N <= 500) cow stalls conveniently numbered
1..N has a colorful light above it.

At the beginning of the evening, all the lights are off. The cows
control the lights with a set of N pushbutton switches that toggle
the lights; pushing switch i changes the state of light i from off
to on or from on to off.

The cows read and execute a list of M (1 <= M <= 2,000) operations
expressed as one of two integers (0 <= operation <= 1).

The first operation (denoted by a 0 command) includes two subsequent
integers S_i and E_i (1 <= S_i <= E_i <= N) that indicate a starting
switch and ending switch. They execute the operation by pushing
each pushbutton from S_i through E_i inclusive exactly once.

The second operation (denoted by a 1 command) asks the cows to count
how many lights are on in the range given by two integers S_i and
E_i (1 <= S_i <= E_i <= N) which specify the inclusive range in
which the cows should count the number of lights that are on.

Help FJ ensure the cows are getting the correct answer by processing
the list and producing the proper counts.

PROBLEM NAME: swtch

INPUT FORMAT:

* Line 1: Two space-separated integers: N and M

* Lines 2..M+1: Each line represents an operation with three
        space-separated integers: operation, S_i, and E_i

SAMPLE INPUT (file swtch.in):

4 5
0 1 2
0 2 4
1 2 3
0 2 4
1 1 4

INPUT DETAILS:

Four lights; five commands. Here is the sequence that should
be processed:
        Lights
            1 2 3 4
  Init:     O O O O   O = off  * = on
  0 1 2 ->  * * O O  toggle lights 1 and 2
  0 2 4 ->  * O * *
  1 2 3 ->  1        count the number of lit lights in range 2..3
  0 2 4 ->  * * O O  toggle lights 2, 3, and 4
  1 1 4 ->  2        count the number of lit lights in the range 1..4

OUTPUT FORMAT:

* Lines 1..number of queries: For each output query, print the count
        as an integer by itself on a single line.

SAMPLE OUTPUT (file swtch.out):

1
2
就是一开始所有的灯是灭着的，然后....

可以用线段树解决

/* ***********************************************
Author        :guanjun
Created Time  :2015/10/4 15:30:49
File Name     :1.cpp
************************************************ */
#include <iostream>
#include <cstring>
#include <cstdlib>
#include <stdio.h>
#include <algorithm>
#include <vector>
#include <queue>
#include <set>
#include <map>
#include <string>
#include <math.h>
#include <stdlib.h>
#include <iomanip>
#include <list>
#include <deque>
#include <stack>
#define ull unsigned long long
#define ll long long
#define mod 90001
#define INF 0x3f3f3f3f
#define maxn 100000+10
#define cle(a) memset(a,0,sizeof(a))
#define ls i<<1
#define rs i<<1|1
const ull inf = 1LL << 61;
const double eps=1e-5;
using namespace std;
struct node{
    int l,r,c;
    int sum;
    int dist(){
        return r-l+1;
    }
}nod[maxn*4];
void push_up(int i){
    nod[i].sum=nod[ls].sum+nod[rs].sum;
}
void push_down(int i){
    if(nod[i].c){
        nod[ls].c^=1;
        nod[rs].c^=1;
        nod[ls].sum=nod[ls].dist()-nod[ls].sum;
        nod[rs].sum=nod[rs].dist()-nod[rs].sum;
        nod[i].c=0;
    }
}
void build(int i,int l,int r){
    nod[i].l=l;
    nod[i].r=r;
    nod[i].c=nod[i].sum=0;
    if(l==r){
        return ;
    }
    int mid=(l+r)/2;
    build(ls,l,mid);
    build(rs,mid+1,r);
    push_up(i);
}
void update(int i,int l,int r){
    if(nod[i].l==l&&nod[i].r==r){
        nod[i].c^=1;
        nod[i].sum=nod[i].dist()-nod[i].sum;
        return ;
    }
    push_down(i);
    int mid=(nod[i].l+nod[i].r)/2;
    if(r<=mid)update(ls,l,r);
    else if(l>mid)update(rs,l,r);
    else {
        update(ls,l,mid);
        update(rs,mid+1,r);
    }
    push_up(i);
}
int query(int i,int l,int r){
    if(nod[i].l==l&&nod[i].r==r){
        return nod[i].sum;
    }
    push_down(i);
    int mid=(nod[i].l+nod[i].r)/2;
    //int sum=0;
    if(r<=mid)return query(ls,l,r);
    else if(l>mid)return query(rs,l,r);
    else return query(ls,l,mid)+query(rs,mid+1,r);
}
int main()
{
    #ifndef ONLINE_JUDGE
    freopen("in.txt","r",stdin);
    #endif
    //freopen("out.txt","w",stdout);
    int n,m,po,x,y;
    while(cin>>n>>m){
        build(1,1,n);
        for(int j=1;j<=m;j++){
            scanf("%d%d%d",&po,&x,&y);
            if(po==0)update(1,x,y);
            else printf("%d
",query(1,x,y));
        }
    }
    return 0;
}

 数据 http://contest.usaco.org/TESTDATA/NOV08_1.htm