I am trying to do a program to find the least prime number to be computed such that the prime number divided by 4 different distinct natural numbers leaves a reminder which is the smallest of the 4 natural numbers.
Example 1
Input : 3 4 5 1
The smallest input number is 1. So we are looking for the smallest prime P such that P MOD 1 = 1, P MOD 3 = 1, P MOD 4 = 1 and P MOD 5 = 1.
Output : 61
Explanation : 1 is the smallest natural number. The smallest prime number formed by dividing it by 3,4,5,1 results in 61.
Example 2
Input : 3 4 5 2
Output : None
Explanation : Any number divided by 4 leaving reminder 2 has to be an even number
Related
I'm trying to solve programming question, a term called "FiPrima". The "FiPrima" number is the sum of prime numbers before, until the intended prime tribe.
INPUT FORMAT
The first line is an integer number n. Then followed by an integer number x for n times.
OUTPUT FORMAT
Output n number of rows. Each row must contain the xth "FiPrima" number of each line.
INPUT EXAMPLE
5
1 2 3 4 5
OUTPUT EXAMPLE
2
5
10
17
28
EXPLANATION
The first 5 prime numbers in order are 2, 3, 5, 7 and 13.
So:
The 1st FiPrima number is 2 (2)
The 2nd FiPrima number is 5 (2 + 3)
The 3rd FiPrima number is 10 (2 + 3 + 5)
The 4th FiPrima number is 17 (2 + 3 + 5 + 7)
The 5th FiPrima number is 28 (2 + 3 + 5 + 7 + 13)
CONSTRAINTS
1 ≤ n ≤ 100
1 ≤ x ≤ 100
Can anyone create the code ?
We are given array-'a' and array-'b' consisting of positive integers.
How can I count all the permutation of array 'a' which are strictly lexicographically smaller than array-'b'?
Arrays can contain as many as 10^5 integers(positive)
Example:
1 2 3 is lexicographically smaller than 3 1 2
1 2 3 is lexicographically smaller than 1 4 5.
I would like the solution to be in C++.
Input : 3
1 2 3
2 1 3
Output : 2
Only permutations 1,2,3 and 1,3,2 are lexicographically smaller than 2 1 3
Let's just tackle the algorithm. Once you get that figured out, the implementation should be pretty straightforward. Does this look like it does what you're looking for?
Pseudo code:
function get_perms(a,b)
#count the number of digits in a that are <b[0]
count = sum(a<b[0])
Nperms = (len(a)-1)! #modify this formula as needed
N = count*Nperms
if sum(a==b[0]) > 0
remove 1 b[0] from a
# repeat the process with the substring assuming a[0]==b[0]
N += sum(a==b[0])*get_perms(a,b[1:end])
return N
main()
get_perms(a,b)
Edit: I did a little searching. I believe that this is what you are looking for.
I have a program in which I have to generate all r-digit numbers (if r is 2 - all 2-digit numbers) among n digits (these ought to be all numbers from 1 to n inclusive). My question is how can I do this recursively or iteratively, for example if n = 3 and r = 2, the result should be 12 13 21 23 31 32.
I need help finding the formula of the sequence for the next problem.
What I think and have for now is Sn=n(10^n-1)/9 but it just works in some cases...
Here is the description of the problem:
Description
Sn is based upon the sequence positive integers numbers. The value n can be found n times, so the first 25 terms of this sequence are as follows:
1 2 2 3 3 3 4 4 4 4 5 5 5 5 5 6 6 6 6 6 6 7 7 7 7...
For this problem, you have to write a program that calculates the i-th term in the sequence. That is, determine Sn(i).
Input specification
Input may contain several test cases (but no more than 10^5). Each test case is given in a line of its own, and contains an integer i (1 <= i <= 2 * 10^9). Input ends with a test case in which i is 0, and this case must not be processed.
Output specification
For each test case in the input, you must print the value of Sn(i) in a single line.
Sample input
1
25
100
0
Sample output
1
7
14
Thanks solopilot! I made the code but the online judge show me Time Limit Exceeded, what could be my error?
#include <iostream> #include <math.h> using namespace std; int main() {int i;
int NTS;
cin>>i;
while (i>=1){
NTS=ceil((sqrt(8*i+1)-1)/2);
cout<<" "<<NTS<<endl;
cin>>i;
}
return 0;}
F(n) = ceiling((sqrt(8*n+1)-1)/2)
Say F(n) = a.
Then n ~= a * (a+1) / 2.
Rearranging: a^2 + a - 2n ~= 0.
Solving: a = F(n) = (-1 + sqrt(1+8n)) / 2.
Ignore the negative answer.
The pattern looks like a pyramid.
Level : 1 3 6 10 15 21 28...
No : 1 2 3 4 5 6 7...
Level = n(n+1)/2 => elements
3 = 3*4/2 => 6
6 = 6*7/2 => 21
Let f(k) = y where k is the y-th number in the increasing sequence of non-negative integers with
the same number of ones in its binary representation as k, e.g. f(0) = 1, f(1) = 1, f(2) = 2, f(3) = 1, f(4)
= 3, f(5) = 2, f(6) = 3 and so on. Given k >= 0, compute f(k)
many of us have seen this question
1 solution to this problem to categorise numbers on basis of number of 1's and then find the rank.i did find some patterns going by this way but it would be a lengthy process. can anyone suggest me a better solution?
This is a counting problem. I think that if you approach it with this in mind, you can do much better than literally enumerating values and checking how many bits they have.
Consider the number 17. The binary representation is 10001. The number of 1s is 2. We can get smaller numbers with two 1s by (in this case) re-distributing the 1s to any of the four low-order bits. 4 choose 2 is 6, so 17 should be the 7th number with 2 ones in the binary representation. We can check this...
0 00000 -
1 00001 -
2 00010 -
3 00011 1
4 00100 -
5 00101 2
6 00110 3
7 00111 -
8 01000 -
9 01001 4
10 01010 5
11 01011 -
12 01100 6
13 01101 -
14 01110 -
15 01111 -
16 10000 -
17 10001 7
And we were right. Generalize that idea and you should get an efficient function for which you simply compute the rank of k.
EDIT: Hint for generalization
17 is special in that if you don't consider the high-order bit, the number has rank 1; that is, f(z) = 1 where z is everything except the higher order bit. For numbers where this is not the case, how can you account for the fact that you can get smaller numbers without moving the high-order bit?
f(k) are integers less than or equal to k that have the same number of ones in their binary representation as k.
For example, k needs m bits, that is k = 2^(m-1) + a, where a < 2^(m-1). The number of integers less than 2^(m-1) that have the same number of bits as k is choose(m-1, bitcount(k)), since you can freely redistribute the ones among the m-1 least significant bits.
Integers that are greater than or equal to 2^(m-1) have the same most significant bit as k (which is 1), so there are f(k - 2^(m-1)) of them. This implies f(k) = choose(m-1, bitcount(k)) + f(k-2^(m-1)).
See "Efficiently Enumerating the Subsets of a Set". Look at Table 3, the "Bankers sequence". This is a method to generate exactly the sequence you need (if you reverse the bit order). Just run K iterations for the word with K bits. There is code to generate it included in the paper.