One example of a problem that is NP$-$hard but can be approached with heuristics, similar to the Traveling Salesman Problem $($TSP$),$ is the "Graph Partitioning Problem" $($GPP$).$ The Graph Partitioning Problem involves dividing the vertices of a graph into a specified number of subsets while minimizing the number of edges that cross between subsets.

Formally, given an undirected graph $G=(V,E)$ and an integer $k,$ the goal is to partition the vertex set $V$ into $k$ subsets $V1,V2,$dots,$Vk$ in a way that minimizes the number of edges between different subsets.

The Graph Partitioning Problem is known to be NPhard, as finding an optimal partition is computationally challenging. However some approximation algorithms exist.

Design an algorithm to solve this problem in an efficient way and determine the computational complexity. You may implement the algorithm using Java, Python etc.