360. Sort Transformed Array

Given asortedarray of integersnumsand integer valuesa,bandc. Apply a function of the form f(x) =ax2+bx+cto each elementxin the array.

The returned array must be insorted order.

Expected time complexity:O(n)

Example:
nums = [-4, -2, 2, 4], a = 1, b = 3, c = 5,
Result: [3, 9, 15, 33]
nums = [-4, -2, 2, 4], a = -1, b = 3, c = 5
Result: [-23, -5, 1, 7]

根据一元二次方程公式， a > 0  U型曲线， a < 0 U型向下曲线。