Zero Array Transformation I

Given an array nums and a sequence of interval queries where each query lets you decrement any subset of elements in that interval by 1, determine whether you can pick subsets for each query so that every element i is decremented exactly nums[i] times (making the array all zeros). The core challenge is a feasibility check: can the per-index decrement requirements be satisfied using only the unit-decrement operations constrained to the given intervals (can be modeled as a flow/interval-covering problem).