jumble with numbers

In NASA, two researchers, Mathew and John, started their work on a new planet, but while practicing research they faced a mathematical difficulty. In order to save the time they divided their work.
So scientist Mathew worked on a piece and invented a number computed with the following formula:
A Mathew number is computed as follows using the formula:
H(n) = n(2n-1)
And scientist John invented another number which is built by the following formula which is called John number.
T(n) = n(n+1)/2
Now Mathew and John are jumbled while combining their work. Now help them combine their research work by finding out number in a given range that satisfies both properties. Using the above formula, the first few Mathew-John numbers are:
1 6 15 28 …

Input Format:

Input consists of 3 integers T1,T2,M separated by space . T1 and T2 are upper and lower limits of the range. The range is inclusive of both T1 and T2. Find Mth number in range [T1,T2] which is actually a Mathew-John number.


Line 1

T1 T2 M,where T1 is upper limit of the range, T2 is lower limit of the range and M ,where Mth element of the series is required
Constraints:

0 < T1 < T2 < 1000000


Output Format:

Print Mth number from formed sequence between T1 and T2(inclusive).

Line 1
For Valid Input,print

Print Mth number from formed sequence between T1 and T2
Or
No number is present at this index

For Invalid Input,print

Invalid Input


Sample Input and Output

SNo. Input Output
1
90 150 2

120
2
20 80 6

No number is present at this index
3
-5 3 a

Invalid Input

plzzzzzz.....give me sollution for this thread...its very urgent...:(

Quote:

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Originally Posted by Tejaswi Godavarthi

plzzzzzz.....give me sollution for this thread...its very urgent...:(

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It may be urgent to you, but this has the look of an assignment which if it is we won't be providing a ready made answer for you as that would be classed as cheating. If this is an assigment, have a read of
http://forums.codeguru.com/showthrea...ork-assignment

Until you can provide some code for us to comment upon, possibly the best advice we could give is to ask how you would do this without a computer using just pen and paper? Once you know how to do it manually, then that can be expressed as an algorithm and then a program design can be done and finally a program can be coded to implement the algorithm/design.

# Author Pawan


i=1
count=0
try:
listi= list(map(int,input().split(" ")))
except:
print("Invalid Input")
exit()
ll=listi[0]
ul=listi[1]
k=listi[2]
num=0
while num<=ul:
num=i*(2*i-1)
# print(num)
if num>=ll and num<=ul:
count=count+1
if count==k:
print(num)
break
i=i+1
if count<k:
print("No number is present at this index")

Quote:

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Originally Posted by coder07

# Author Pawan


i=1
count=0
try:
listi= list(map(int,input().split(" ")))
except:
print("Invalid Input")
exit()
ll=listi[0]
ul=listi[1]
k=listi[2]
num=0
while num<=ul:
num=i*(2*i-1)
# print(num)
if num>=ll and num<=ul:
count=count+1
if count==k:
print(num)
break
i=i+1
if count<k:
print("No number is present at this index")

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What is it? :confused: :confused: :confused:

the solution to the above question in python

This is a C++ forum - not a python one!

Quote:

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Originally Posted by coder07

the solution to the above question in python

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The sample inputs and outputs are easier to understand if formatted like this i think,

SNo / Input / Output
-----------------------
1 / 90 150 2 / 120
2 / 20 80 6 / No number is present at this index
3 / -5 3 a / Invalid Input

The brute force solution must be to generate two lists, one for Mathew numbers and one for John numbers, of all n within the given range. The lists are then scanned for equal numbers, that is Mathew-John numbers. Finally the M'th Mathew-John number is chosen.

Finding equal numbers in two sorted lists is a standard O(N) problem (two pointers are advanced successively). Since the Mathew and John numbers appear in sorted order no actual list data structures are necessary.

Quote:

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Finding equal numbers in two sorted lists is a standard O(N) problem (two pointers are advanced successively). Since the Mathew and John numbers appear in sorted order no actual list data structures are necessary.

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std::set_intersection() could be used.

For H, given a lower limit of x ie n(2n-1) > x, then the starting point of n is given by

n = int((1 + sqrt(1 + 8x))/4)

Similarly for T, given a lower limit of y ie n(n+1)/2 > y, then the starting point is given by

n = int((-1 + sqrt(1 + 8y))/2)

This avoids needles computations and matches. Obviously when T(n) and H(n) exceed the upper limit, then also the computations for that set also stop.

Quote:

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Originally Posted by 2kaud

For H, given a lower limit of x ie n(2n-1) > x, then the starting point of n is given by

n = int((1 + sqrt(1 + 8x))/4)

Similarly for T, given a lower limit of y ie n(n+1)/2 > y, then the starting point is given by

n = int((-1 + sqrt(1 + 8y))/2)

This avoids needles computations and matches. Obviously when T(n) and H(n) exceed the upper limit, then also the computations for that set also stop.

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This thread is from 2013