Compile the program using gcc simualator.c -lpthread
You can quickly change the number of people by changing NUMBER_OF_INDIVIDUALS from 23 to your desired number
You can quickly change the number of people by changing DAYS from 365 to your desired number
You can quickly change the number of people by changing NUMBER_OF_SIMULATIONS from 1000000 to your desired number
You can check out the paradox here : https://en.wikipedia.org/wiki/Birthday_problem