Question about sorting a user input for array

[jimmy107]

Hello, I need help with my code. Were supposed to be able to sort an array which is user input, but the first number they input is supposed to be the length of the array, and everything after that is the actual array.
Here is my code:

#include <iostream>
#include <iomanip>

using namespace std;


int main()
 {
   
    int size;
    int list[80];
    bool isSorted (const int list[], int size);
    void printarray(const int list[], int size);
  
    for(int i = 0; i<80; i++)
     {
    cout << "Enter a value for the length of the list, then enter list: \n";
        cin >> size;
        cin >> list[i];
     }
 }
    
    
    


bool isSorted (const int list[], int size)
 {
    for(int i=0;i<size;++i)
   {
    
            if (list[i] > list[i+1])
            {
                cout << "The list is not sorted";
                return false;
              }
       }
    cout << "The list is sorted";
        return true;
   }
        

I'm stuck on how I'm supposed to use the first digit of input for the array size.

Thankyou!

[LB]

Are you allowed to use std::vector? If not, do you know how to use dynamic memory? If not, is there an upper limit on the size the user can enter?

Also, please use code tags:
http://www.cplusplus.com/articles/jEywvCM9/

[jimmy107]

The complete question reads as follows:

"Write the following function that returns true if the list is already sorted in increasing order:

bool isSorted(const int list[], int size)

Write a test program that prompt the user to enter a list and displays whether the list is sorted or not. Here is a sample run. Note that the first number in the input indicates the number of elements in the list. This number is not part of the list. Assume the maximum list size is 80."

example of output:

Enter list: 5 2 1 4 5 6
List is not sorted

Enter list: 5 1 2 3 4 5
The list is sorted


we haven't been taught vectors yet so I'm assuming we can't use them and no i don't know how to use dynamic memory. And i think the first digit in the input is the only limit we can put on the array.


Thank you for responding!

[cire]

#include <iostream>

using namespace std;

bool isSorted(const int*, int);
void printArray(const int*, int);

int main()
{
    const int max_size = 80;
    int list[max_size];

    int size ;

    cout << "Enter list: ";
    cin >> size;    // We don't want to repeatedly enter the size, 
                    // so this shouldn't be in the body of the loop.

    for (int i = 0; i < size; ++i)
        cin >> list[i];

    // ...
}

[jimmy107]

oohhhhhh ok I see what I did! Thank you! How would I reference the main function to the isSorted function and the printArray function? That stuff has always been a bit shady to me sorry!

[kannanmj]

#include <iostream>

using namespace std;

bool isSorted(const int*, int);

int main()
{
    const int max_size = 80;
    int list[max_size];
    unsigned int size;

    // Get the array size.
    cout << "Enter size (max 80): ";
    cin >> size;

    // Get the elements.
    cout << "Enter " << size << " integers\n";
    for (int i = 0; i < size; ++i)
        cin >> list[i];

    // Check if the list is sorted.
    isSorted(list, size);

    cout << endl;
    return 0;
}

bool isSorted (const int list[], int size)
 {
   for(int i=0; i < size-1; ++i)
   {
     if (list[i] > list[i+1])
     {
       cout << endl << "The list is not sorted";
       return false;
     }
   }
   cout << endl << "The list is sorted";
   return true;
}

Note: In function isSorted the loop check should be "size-1" because the last element in the array should not be compared with junk value out of bound of the array. Also when there is only one element in the list there is nothing (no other element) to compare it with.

[jimmy107]

Ok I got it. Thank you to all who posted!!