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
vivek_shah98: 2018-03-25 04:54:54

Same as FLIPCOIN problem on Codechef....

imperfectboy: 2018-03-15 14:05:37

changing cout to printf ==== time 0.65---->0.35 !!!!

imperfectboy: 2018-03-15 13:49:52

first lazy propagation problem !! phewww

hitman007: 2018-02-11 18:44:06

Anyone got accepted in Java ? I am getting TLE at test# 10.

siva2697: 2018-02-11 16:53:31

Funny and Nice
Use faster input method

Last edit: 2018-02-11 20:22:23
shubham_kira: 2018-02-10 08:23:49

what do you mean @rareguy

ramini1996: 2018-02-03 12:45:02

For 10th test case keep in mind that if you want to flip a range which already needs to be flipped then there is no need to flip at all. So, take care of it (just flip the boolean values of left and right child in lazy array instead of setting them to true !!! BTW nice question !!!

shub120798: 2018-01-31 19:10:19

segtree+node+lazy+swap. Finally learnt how to apply lazy propagation on nodes of seg tree

amitboss: 2018-01-29 18:31:55

ac in 1 go

spojabhi: 2017-12-24 00:24:54

use int otherwise 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