#include #include //Library for "rand()" and "srand()". using namespace std; int number; //This function will print 10 pseudo-random numbers. void printNumbers() { for(int i = 0; i < 10; i++) { /* The "rand()" function will generate a pseudo-random number. In this case, between 0 to 99. number = rand() % 100; Range: from 0 to 99. number = rand() % 50; Range: from 0 to 49. number = rand() % 100 + 1; Range: from 1 to 100. */ number = rand() % 100; //The function "rand()" really don't make true random numbers, it needs a "seed", a initial state to make random calculations to numbers to look like random. See below "srand()". cout << "Try #" << i+1 << ": " << number << endl; } } int main() { //The "srand()" function sets a "randomness seed". The parameter of that function will be the "seed" for the "rand()" function. Let's set some seeds. Run the code a few times and see the table. What is happening? srand(1); cout << "Randomness seed: 1" << endl << "==========" << endl; printNumbers(); srand(2); cout << endl << "Randomness seed: 2" << endl << "==========" << endl; printNumbers(); srand(3); cout << endl << "Randomness seed: 3" << endl << "==========" << endl; printNumbers(); //No matter how many times you run the code, the values will be always the same because THE SEED DON'T CHANGE. This is pseudo-random numbers. How can we make a (kinda) real random number generator? See part #2. return 0; }

[Randomness #1] Pseudo-random numbers