LITE - Light Switching

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 <= 100,000) 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 <= 100,000) operations expressed as one of two integers (0 <= operation <= 1).

The first kind of 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 kind of 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.


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


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


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


hide comments
GAURAV CHANDEL: 2015-04-26 13:07:41

Hey , We are lazy..and it gives AC....

Ankit: 2015-02-17 01:02:31

use scanf and printf instead of cout and cin .... gives TLE
choose appropriate number of nodes in the tree,if less nodes are chosen WA

Last edit: 2015-02-17 01:03:27
screw_1011: 2015-02-04 08:13:07

My first lazy feeling :D :P
good question :)

Last edit: 2015-02-04 08:17:18
Sudharsansai: 2015-01-25 06:50:09

Wow...For the first time I am feeling LAZY....

DEEPAK KUMAR SINGH: 2015-01-13 06:30:48

Wonderful..My first lazy Propogation+segment tree...

californiagurl: 2014-12-28 16:48:08

cant believe my own stupidity.... got so many TLE for using cout -_-

Last edit: 2014-12-29 03:06:50
Nilesh Sah: 2014-12-19 13:56:46

long long gives TLE.. AC with int

hippie: 2014-12-17 14:16:53

There's nothing mysterious about the 10th test-case at all, a trivial flaw related to calculation of lit lights by combining lazy updates and current values was my cause of WA. Just go through the code carefully once.

Igor Morozov: 2014-11-02 12:30:24

Please, give some example with the same trick, as in test 10. I'm using segment tree with lazy propagation, updating the nodes everywhere, where needed, and pushing down correctly, still got WA. My code:

Chetan gulati: 2014-10-25 20:30:22

Use faster input output to avoid TLE.

Added by:Iqram Mahmud
Time limit:1s
Source limit:50000B
Memory limit:1536MB
Cluster: Cube (Intel G860)
Languages:All except: OBJC VB.NET
Resource:USACO November 08