Combinatorial Optimization

There are some balloons on a wall represented by 2D coordinates points, where points[i] = [x_start, x_end]. Arrows are shot vertically from the ground; an arrow at position x bursts every balloon whose x_start <= x <= x_end. Return the minimum number of arrows required to burst all balloons.

You have some sticks with positive integer lengths. You can connect any two sticks of lengths x and y into a new stick of length x + y at a cost of x + y. Return the minimum total cost to connect all sticks into one stick. (Greedy with a min-heap: always combine the two shortest sticks.)