20 lines
409 B
Ruby
20 lines
409 B
Ruby
|
#Fitcher-Yates shuffling algorithm
|
||
|
|
#(start from last element,swap with random element from the array,decrement array size by one and repeat until array size is 1)
|
||
|
|
#Time-complexity: O(n)
|
||
|
|
|
||
|
|
def shuffle(arr)
|
||
|
|
n=arr.length
|
||
|
|
for i in (n-1).downto(1)
|
||
|
|
j=Random.rand(i+1)
|
||
|
|
swap(arr,i,j)
|
||
|
|
end
|
||
|
|
print arr
|
||
|
|
end
|
||
|
|
|
||
|
|
def swap(arr,i,j)
|
||
|
|
temp = arr[i]
|
||
|
|
arr[i] = arr[j]
|
||
|
|
arr[j] = temp
|
||
|
|
end
|
||
|
|
|
||
|
|
shuffle([1,2,3,4,5,6])
|