Struct and class

Today we want to implement a undirected Connected Graph AlgorithmBased on the previous experience in C ++, I used struct. Do I use struct or class for implementation in C?
I checked some information to list the differences between struct and class:
1. struct is a value reference, while class is an object reference.
2. C # Not Allowed StructHas the default constructor. The runtime database inserts a constructor that initializes all values to the zero state. That is to say, struct can not be instantiated.
3. When arrays are used, struct is more efficient than class, but it is less efficient when collections is used, mainly because struct is a value type and requires boxing and unboxing.

Therefore, it is better to use struct to implement this algorithm.