Found that this forms various disjoint cycles between a and b ,
If b is all -1 greedily map to values from 'a' such that a[bi] = b[ai]
after all cycle discovery fill 'b' greedily if -1
if cycles cant form (values collide), return NO.
BUT HTF DO I CODE THESE ๐ซ ๐ญ๐ญ
#cf#dsa