In the permutations of the numbers 1 to n, count the number of permutations in which exactly m elements are greater than the previous element.
Example -
n=4;
m=2;
%permutations in which exactly 2 numbers are greater than the previous element
y=[1 3 2 4
1 4 2 3
1 2 4 3
2 3 1 4
4 1 2 3
2 4 1 3
2 1 3 4
1 3 4 2
2 3 4 1
3 1 2 4
3 4 1 2]
%11 permutations
out=11;
n=3;
m=0;
%permutations in which exactly 0 numbers are greater than the previous element
y=[3 2 1];
%only 1 permutation
out=1;
n=3;
m=1;
%permutations in which exactly 1 numbers are greater than the previous element
y=[1 2 3
1 3 2
2 3 1
2 1 3];
%4 permutations
out=4;
n=3;
m=2;
%permutations in which exactly 2 numbers are greater than the previous element
y=[1 2 3];
%only 1 permutation
out=1;
The task, here, is to calculate the output for all values of m (0 to n-1) given a natural number n, and output it in a row vector.
Check test case #1 for restricted functions.
Solution Stats
Problem Comments
Solution Comments
Show comments
Loading...
Problem Recent Solvers7
Suggested Problems
-
Replace NaNs with the number that appears to its left in the row.
3069 Solvers
-
2279 Solvers
-
Find a subset that divides the vector into equal halves
402 Solvers
-
Is this triangle right-angled?
6757 Solvers
-
Numbers spiral diagonals (Part 1)
306 Solvers
More from this Author44
Problem Tags
Community Treasure Hunt
Find the treasures in MATLAB Central and discover how the community can help you!
Start Hunting!