Chapter 2: Basic Abstract Data Types. Problem 2.2.a

//list as an array - provide insert(), delete() and locate() functionality

#include <stdio.h>

void list_delete( int* array, int& size, int elemToDelete ); 
int locate( int* array, int size, int elemToLocate); 
void insert( int* array, int& size, int elemToInsert ); 
void PrintArray( int* array, int size); 

void main()
{
    int array[100];
    array[0] = 1;
    array[1] = 2;
    array[2] = 3;
    array[3] = 4;
    array[4] = 5;
    array[5] = 6;
    array[6] = 7;

    int size = 7; //current size of the array. 

    //lets use the functions.
    int pos = -1;
    pos = locate( array, size, 0 );
    if( pos == -1 )
        printf("element 0 not found." ); 
    else
        printf("element 0 found at position [%d].\n", pos );

    pos = locate(array, size, 6);
    if( pos == -1 )
        printf("element 6 not found." ); 
    else
        printf("element 6 found at position [%d].\n", pos );

    PrintArray(array, size); 

    //insert
    insert( array, size, 0);
       insert( array, size, 10 ); 
    insert( array, size, 11 ); 
    
    PrintArray( array, size);
    
    //delete
    list_delete( array, size, 0 ); 
    list_delete( array, size, 1 ); 
    list_delete( array, size, 2 ); 

    PrintArray( array, size ); 
}

int locate( int* array, int size, int elemToLocate)
{
    for( int i = 0; i < size; i++ )
    {
        if( array[i] == elemToLocate )
            return i;
    }
    return -1;
}

void insert( int* array, int& size, int elemToInsert )
{
    //find position of where to insert the elem
    int i; 
    for( i=0; i< size; i++ )
    {
        if( array[i] > elemToInsert )
            break;
    }

    if( i != size ) 
    {
        //we need to move the array in right direction
        for( int j = size; j > i; j-- )
        {
            array[j] = array[j-1];
        }
    }
    array[i] = elemToInsert;
    size++; 
}

void list_delete( int* array, int& size, int elemToDelete )
{
    //find pos of element to delete.
    int i;
    for( i = 0; i < size; i++ )
    {
        if( array[i] == elemToDelete )
            break;
    }
    if( i == size-1 )
    {
        //last elem needs to be deleted
        size--; 
    }
    else if( i == size )
    {
        //element not found
    }
    else
    {
        /* need to move the elements to the left. */ 
        for( int j = i; j < size-1; j++ )
            array[j] = array[j+1];
        size--; 
    }
}

void PrintArray( int* array, int size)
{
    printf("\n Array is --> \n" );
    printf("\n");
    for( int i = 0; i < size; i++ )
    {
        printf("[%d]\n", array[i] );
    }
    printf("\n");
    printf("End of array.\n");
}