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Interview Question for Senior Software Engineer at Goldman Sachs:
Sep 8, 2009
Classix 2 eggs problem . * You are given 2 eggs. * You have access to a 100-storey building. * Eggs can be very hard or very fragile means it may break if dropped from the first floor or may not even break if dropped from 100 th floor.Both eggs are identical. * You need to figure out the highest floor of a 100-storey building an egg can be dropped without breaking. * Now the question is how many drops you need to make. You are allowed to break 2 eggs in the process
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1 of 2 people found this helpful
Oct 7, 2009
9.8m/sec^2 is the acceleration due to gravity, not velocity. No falling object can ever achieve terminal velocity, as you incorrectly stated.
Secondly, although your answer is correct, your formula is wrong. The general form is ceiling[ (sqrt(8n+1)-1) / 2], with n = # of stories.
Secondly, although your answer is correct, your formula is wrong. The general form is ceiling[ (sqrt(8n+1)-1) / 2], with n = # of stories.
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Dec 12, 2009
use first egg to reduce the problem half size and then use second egg progressively to find answer. 100/2 then 50/2 then 25/2 then 13/2 then 7/2 then 4/2 then2/2 but while you start start dropping in reverse order from first, second...
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0 of 1 people found this helpful
Dec 12, 2009
use first egg to reduce the problem half size and then use second egg progressively to find answer. 100/2 then 50/2 then 25/2 then 13/2 then 7/2 then 4/2 then2/2 but while you start start dropping in reverse order from first, second...
Otherwise simple mathematical inequality eqn q(q+1)/2>=100 will solve the problem.
Otherwise simple mathematical inequality eqn q(q+1)/2>=100 will solve the problem.
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0 of 1 people found this helpful
Dec 30, 2009
Lets assume you divide the floors into y partitions of size x each.
The least value of y gives the best solution:
here, x^y +x-1 =99 for the worst case best satisfactory ans.
The least value of y gives the best solution:
here, x^y +x-1 =99 for the worst case best satisfactory ans.
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3 of 3 people found this helpful
Feb 27, 2010
The problem is harder as you are only allowed to throw 2 eggs. Thus, the second throw operation is a linear operation. Thus, the problem is reduced to finding a solution which requires minimum number for 2nd linear throw.
Let's say that x is the optimal number of throws required. And, for time being let's say x=20. Then,
You would do the first throw from 20th floor and if egg breaks you would do a linear operation of throws from 1st to 20th floor to find which floor the egg breaks.
However, if the egg doesn't break then you will throw from 39th floor, as you are now one throw less. Following this logic
20
39
57
73
88
102 but you only have 100 floors thus this is not the right answer.
x + (x-1) + (x-2) + ... + 1 = 100
x(x+1)/2=100
which gives x=14 which is the optimal number of throws required.
Let's say that x is the optimal number of throws required. And, for time being let's say x=20. Then,
You would do the first throw from 20th floor and if egg breaks you would do a linear operation of throws from 1st to 20th floor to find which floor the egg breaks.
However, if the egg doesn't break then you will throw from 39th floor, as you are now one throw less. Following this logic
20
39
57
73
88
102 but you only have 100 floors thus this is not the right answer.
x + (x-1) + (x-2) + ... + 1 = 100
x(x+1)/2=100
which gives x=14 which is the optimal number of throws required.
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0 of 8 people found this helpful
by matt:
The answer is 14. n(n+1)/2