How do I generate a random number between two variables that I have stored? [duplicate]

Question

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Generating random integer from a range

I am trying to create a program where the computer guesses a number the user has in his/her mind. The only user input required is whether the guess was too high, too low, or correct. I'm having a problem generating a random number between two variables that store the min and max based on previous guesses. Here is my code:

    #include <iostream>     #include <cstdlib>     #include <ctime>      using namespace std;      int main()     {         srand(static_cast <unsigned int> (time(0)));          int compGuess = rand() % 100 +1; //Generates number between 1 - 100         int highestNumber = 100;         int lowestNumber = 1;         char ready;         char highLowSuccess;         bool success;         int tries = 0;           cout << "Please pick a number between 1 - 100. I will guess your number. Don't tell me what it is!\n\n";           do         {             cout << "Are you ready? (y/n)\n\n";             cin >> ready;              if (ready == 'y')             {                 do                 {                     cout << "Is your number " << compGuess << "?\n\n";                     cout << "High, Low or Success?";                     ++tries;                     cin >> highLowSuccess; //User input telling the computer whether its too high, too low, or a success                      if (highLowSuccess == 'h') //Executes code if number guessed was too high.                     {                          highestNumber = compGuess - 1; //Stores variable indicating the highest possible number based on user input                         compGuess = rand() % highestNumber +1; //Generates a new random number between 1 and the new highest possible number                         success = false;                     }                      else if (highLowSuccess == 'l') //Executes code if number guessed was too low.                     {                         lowestNumber = compGuess + 1;//Stores variable indicating the lowest possible number based on user input                         compGuess = (rand() % highestNumber - lowestNumber + 1) + lowestNumber // <---- Not producing the desired result                         success = false;                     }                      else if (highLowSuccess == 's') //Executes code if the computer's guess was correct.                     {                         cout << "I guessed your number! It only took me " << tries << " tries!";                         success = true;                     }                   } while (success != true);             }               else             {              continue;             }         } while (ready != 'y');        return 0;      } 

highestNumber is what the max should be and lowestNumber is what the min should be. I need an equation that lets me generate a random number while taking the highest and lowest possible numbers into account.

Forgive me if the answer is really simple, I'm a noob programmer. xD

Answer 1

To generate a random number between min and max, use:

int randNum = rand()%(max-min + 1) + min; 

(Includes max and min)