An apparatus and method of low complexity optimization solver for path smoothing with constraint variation are herein disclosed. According to one embodiment, an apparatus includes an L1 central processing unit (CPU) configured to transform an L1 trend filtering problem to a primal-dual linear programming (LP) optimization problem pair; and an L1 arithmetic logic unit (ALU) connected to the L1 CPU and configured to solve a primal problem of the primal-dual LP optimization problem pair with an extended full tableau simplex method.