You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
33 lines
788 B
Ruby
33 lines
788 B
Ruby
#Given an array A[] consisting 0s, 1s and 2s, put all 0s first, then all 1s and all 2s in last.
|
|
##Brute-force: Count 0s and 1s (using 2 varibales)and rewrite array first with counted zeros then by counted 1s and then by 2s
|
|
#Time-complexity:O(n),Auxiliary-space:O(1)
|
|
|
|
|
|
##Algorithm: Dutch National Flag Algorithm
|
|
#Time-complexity:O(n),Auxiliary-space:O(1)
|
|
|
|
|
|
def segregate(a)
|
|
right=a.length-1
|
|
left=0
|
|
current=0
|
|
while(current<=right)
|
|
if a[current]==0
|
|
swap(a,left,current)
|
|
left+=1
|
|
current+=1
|
|
elsif a[current]==2
|
|
swap(a,right,current)
|
|
right-=1
|
|
else
|
|
current+=1
|
|
end
|
|
end
|
|
print a
|
|
end
|
|
|
|
def swap(a,i,j)
|
|
a[i],a[j]=a[j],a[i]
|
|
end
|
|
|
|
segregate([0, 1, 1, 0, 1, 2, 1, 2, 0, 0, 0, 1]) |