The purpose of this programming assignment is to (A) write the Sparse General Matrix-Matrix Multiplication (SpGEMM) variant for multiplying sparse matrices, (B) Use SpGEMM to solve the All-Pairs Shortest Path (APSP) problem. I primarily worked in implementing SpGEMM, while my friend Ilias Baali worked on APSP problem. Please read the problem description in PA3_updated to go through the problem statement. The codes were run on the PACE cluster at Georgia Tech.