Insert element into array C

Question

I have an array of numbers that has been sorted in before, so there's no need to sort it, I need to insert an given value, named it val, at a valid position in my array.

My program works for a given value that is smaller than the last one, but for the case where the value is bigger than the last one, my program just doesn't want to insert the value.

For example, for the array {1, 2, 3, 4, 6} and the value 5, the array should be {1, 2, 3, 4, 5, 6}, but for the value 7 my array is looking like {1, 2, 7, 4, 6, 0}.

#include <stdio.h>

void insert(int val, int *n, int v[])
{
    int index;
    index = n - 1;
    if (n == 0)
    {
        v[0] = val; // check if array is empty
        n = n + 1; // v[0] becomes the given value
    }              // increase size of array
    if (val > v[index])
    {
        v[index+1] = val; // given value is bigger than the last value in array
        n = n + 1; // increase size
    }
    else
    {
        while (index >= 0 && v[index] > val)
        {
            v[index+1] = v[index]; //shift items to the right
            index--;
        }

        v[index + 1] = val; //after moving elements to the right
        n = n + 1;   // i set the value to the valid position
    }
}

void display(int n, int v[])
{
    int i;
    for (i = 0;i < n; i++)
        printf("%d ", v[i]);
}

int main(void)
{
    int v[10] = { 12, 23, 34, 41, 69, 71, 81, 91, 100 };
    int n;
    n = 9; // size of array
    insert(101,n,v); // 101 is given value to insert
    display(n,v);
    return 0;
}

int *n ... int index = n - 1; would raise a warnings on a well enabled compiler. Save time, avoid embarrassment and enable warnings. — chux
– chux, Commented Jun 5, 2017 at 21:37
i need the N to be passed with the increased value after the insertion to the display function that prints the array, it's true that it shown warnings on my computer but I am still struggling with pointers — kubectlgetpods
– kubectlgetpods, Commented Jun 5, 2017 at 21:40

Stargateur · Accepted Answer · 2017-06-05 22:09:34Z

3

You have a couple of mistakes:

You are passing int instead of int * so you're not able to update array size
You are not correctly placing value in the array

This is how your code should look like:

#include <stdio.h>

void insert(int val, int *nPtr, int v[]);
void display(int n, int v[]);

int main(void) {
  int v[10] = {12, 23, 34, 41, 69, 71, 81, 91, 100};
  int n;
  n = 9;
  insert(101, &n, v);
  display(n, v);
  return 0;
}

void insert(int val, int *nPtr, int v[]) {
  int n = *nPtr;
  int i, j;
  int k = 0;

  for (i = 0; i < n + 1; i++)
    if (!k) {
      if (v[i] > val || i == n) {
        for (j = n - 1; j >= i; j--) {
          v[j + 1] = v[j];
        }

        v[i] = val;
        n++;

        k = 1;
      }
    }

  *nPtr = n;
}

void display(int n, int v[]) {
  int i;
  for (i = 0; i < n; i++)
    printf("%d ", v[i]);
  printf("\n");
}

You can also try to insert number on the beginning, for example 0 and it will still work.

edited Jun 5, 2017 at 22:09

Stargateur

27.1k9 gold badges73 silver badges99 bronze badges

answered Jun 5, 2017 at 21:43

dhDPfKCfJdU4JIW4Sc

685 bronze badges

Sign up to request clarification or add additional context in comments.

2 Comments

kubectlgetpods Over a year ago

Thank you! Now i know how to pass the value using pointers. But I will stick to my code and try to improve it, as I need to cover all the possible cases, and I tested yours and for the value 0, that is smaller than the first element of the array, the array looks like {0, 23, 23, ...., 23}. It's true that your code is written better than mine, I can't say no to that, and for the BREAK; I am not allowed to use it in my college admission examen so I tend to avoid it, but thank you! You've been a great help.

dhDPfKCfJdU4JIW4Sc Over a year ago

@MariusJula. I didn't know you're not allowed to use break. Also, thank you for mentioning that my code had a bug. I fixed it and removed break, it now works for all cases.

Collectives™ on Stack Overflow

Insert element into array C

1 Answer 1

2 Comments

Your Answer

Linked

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

2 Comments

Your Answer

Sign up or log in

Post as a guest

Linked

Related