Thread: A few questions

Hi the first question is, how can I set a min and max for the rand function. At the moment i'm seeding from ctime then using

Code:

int theNumber = rand() % max + 1

It picks a number between 0 and 100 then if its too high it sets the max integer to the number just guessed. How can I change the min one.

My second question is:

Code:

#include <iostream>
#include <string>
#include <vector>

using namespace std;

int main()
{
    string input;
    const int MAX_ITEMS = 10;
    int inventoryCount = 0;
    string inventory[MAX_ITEMS];
    vector<string> shopList;
    int shopListCount = 0;
    shopList.push_back("Sword") && (shopListCount++);
    shopList.push_back("Shield" && (shopListCount++);
    shopList.push_back("Firewood") && (shopListCount++);
    
    cout << "Welcome to Ben's Test RPG, input inventory if you want to see what you own, type quit to leave aand type shop to see the shop" << endl;
    
    
    do
    {
         cin >> input;
         
         if(input == "inventory")
                  
                  if(inventoryCount != 0)
                                    
                                    for (int i=0; i < inventoryCount; i++)
                                        
                                        cout << inventory[i];
                                    
                  else
                                    
                                    cout << "Sorry you have no items." << endl;
                                    
         
         if(input == "shop")
         
                  for (int j=0; j < shopListCount; j++)
                      
                      cout << shopList[j];
                  
         if(input == "quit")
         ;
         
         else
         
             cout << "Sorry incorrect choice.";
             
             }while(input != "quit")
             
             }

How can I make it so it adds to my shopListCount when the vector gets pushed back.

Thanks,
Ben

Originally Posted by Chipmunkey

It picks a number between 0 and 100 then if its too high it sets the max integer to the number just guessed. How can I change the min one.

Imagine you could generate a random number between 0 and 50. Now add 50 to this number. You now have a random number between 50 and 100. Make sense?

Why do you need shopListCount at all? Just use shopList.size().

Code:

shopList.push_back("Shield") && (shopListCount++);

Finally... A practical use for high school algebra.

Well we know that rand() % num gives us a number from 0 to (num - 1). So after a few revisions and tests in my head, here's my final answer:
(rand() % (max - (min - 1))) + min

If min = 50 & max = 100 then:

(rand() % (100 - (50 - 1))) + 50
=(rand() % (100 - 49)) + 50
=(rand() % 51) + 50
=(0...50) + 50
=(50...100)