We have an array of Integers, $A$ and we have to find the minimum number that is not the sum of a subset of array using the elements from $L$ to $R$ indices. I was thinking of using coin change DP approach, and outputing the min number with value infinity. But the problem is that the sum of ranges can be as large as 109, and we have about 105 queries of the type $[L,R]$, so I was hoping there'd be a better approach. Can anyone point me in the right direction?
There are 105 elements in the array
Suppose the elements of the array are 1,1,2,7. Then for indices 1 and 4, the smallest number that cannot be formed as a sum is 5. since we can form all 1,2,3,4.