How output is comming out 2

#1

anyone can explain me in detail

#2

hello @deepak147852
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you can pick 1st activity (10,20) and then after finishing it at time 20. you can pick 3rd activity (20,30).
that is how output is coming 2.

#3

no but kaise eak max manage karna hoga and usko count karna hoga kitni bar max aa rha hai

#4

ok ye dekho ek baar -> https://www.studytonight.com/data-structures/activity-selection-problem

implementation->

#5

can you pls, mughe step by step samgha sakte oo achual mai qus kya kah rha hai and jo aapne ans diya usme kya logic lgaya hai.

actually i am new in pair STL. jo aappne kiya step by step samgha skte hai
but start with qus.

#6

hame n activities di hui hain (jinka starting aur ending time hame pata hai).

aur hame batana hai ki maximum kitni activity kar sakte hai.
constraint ye hai ki hum agar koi activity kar rahe hai to us time mein koi aur activity nahi kar sakte.
for example agar hum acitivity (5,15) kar rahe hai to acitvity (7,16) nahi kar sakte kyunki dono ka time overlap kar raha hai.

code->
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yaha pe mein pair read kar raha hu.
cin>>v[i].first >> v[i].second;

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ye activity ko sort kar dega ending time ke basis pe.

image

yaha pe same agorithm implement kiya hai jo article me mention tha.

pair stl-> https://www.geeksforgeeks.org/pair-in-cpp-stl/

#7

ye cmp fun kaise kaam kar rha hai. hamne kyo use kiya usko

#8

yeah poora samgh mai aa gya mughe bas ye cmp fun smgha doo

#9

agar hum iss input ke liye

1
3
10 20
12 15
20 3

without cmp() ka use kre to kya output hoga?

and if isse use karke kre to kya output hoga

#10

image
cmp function me do pair ko compare karne ka logic likha hai.
logic ye hai ki agar dono a ending time same hai to pair ko increasing order of starting time ke basis pe arrange kar do.
isilye(if(a.ss==b.ss) return a.ff < b.ff;
otherwise agar finishing time different hai to increasing order of finishing time ke hisab se isiliye (return a.ss < b.ss);

compare function stl playlist me cover hua hai to ek baar wo playlist dekh lo acche se samjh aa jayega

#11

agar hum compare function use nahi karenge to .
sort function first value of pair ke hisab se sort kar dega.

to iska order after sorting ye hoga->
10 20
12 15
20 3

#12

agar cmp() use krenge to teh aayga naa

12 15
10 20
20 30

#13

ha … . . . . . . .

#14

ok thank you so much aman,