1418. Bound Found

Signals of most probably extra-terrestrial origin have been received and digitalized by The Aeronautic and Space Administration (that must be going through a defiant phase: “But I want to use feet, not meters!”). Each signal seems to come in two parts: a sequence of n integer values and a non-negative integer t. We’ll not go into details, but researchers found out that a signal encodes two integer values. These can be found as the lower and upper bound of a subrange of the sequence whose absolute value of its sum is closest to $t$.

You are given the sequence of $n$ integers and the non-negative target $t$. You are to find a non-empty range of the sequence (i.e. a continuous subsequence) and output its lower index $l$ and its upper index $u$. The absolute value of the sum of the values of the sequence from the $l$-th to the $u$-th element (inclusive) must be at least as close to $t$ as the absolute value of the sum of any other non-empty range.