Optimal Game Strategy-I

#1

PLease guide me for the proper approach for this problem ?

#2

here greedy approach(choosing the max value from the either end) will always not work.
e.g
1 3 8 4

so the simplest approach is choose all the coins of even index or odd index whose sum is greater.
suppose even index coins making greater sum,
then choose the coins in such way that all the odd coins are left for ur opponent

hope this will help u