Given a array with +ve and -ve integer , find the maximum sum such that you are not allowed to skip 2 contiguous elements ( i.e you have to select at least one of them to move forward).
eg :-
10 , 20 , 30, -10 , -50 , 40 , -50, -1, -3
Output : 10+20+30-10+40-1 = 89
Use a recurrence that accounts for that:
dp[i] = max(dp[i - 1] + a[i], <- take two consecutives
dp[i - 2] + a[i], <- skip a[i - 1])
Base cases left as an exercise.