Past exam of the year 1 of the computer science course of the University of Oxford / 2014 / Functional programming, design and analysis of algorithms / 6 / a / Solution

Describe routes by array indices, so repeated entry values cannot confuse positions. Two valid routes areThe first uses jump lengths $2,2,5,1$, bounded respectively by $A[0]=2$, $A[2]=3$, $A[4]=5$, $A[9]=7$. The second uses lengths $2,1,1,4,2$, bounded by $2,3,3,5,2$ at its departing positions. Both reach the final index without landing at the zero entry at index six.