Question

Overview: You will write a program that reads up to 100 numbers from a file. As you read the
numbers, insert them into an array in ascending order.
Specifics:
1A. Write a function called insertIntoSortedArray .
i. It should take three arguments -
a. myArray[ ] : sorted array that should be able to hold at most 100 integers.
b. numEntries : the number of elements inserted so far.
c. newValue : the incoming value to be inserted into the sorted array (i.e.
myArray[]).
ii. The insertIntoSortedArray function should return a count of the elements inserted so
far (i.e. the current size of the array)
This function is defined as follows:
int insertIntoSortedArray ( int myArray[], int numEntries, int newValue);

Answer 1

//This program is written in C
//To convert it to C++, comment the first header line and
//uncomment next two lines as written below.

#include <stdio.h> //for C

//#include <iostream> // for C++
//using namespace std; // for C++

int insertIntoSortedArray (int myArray[], int numEntries, int newValue)
{
   //corner case: array already full
   if(numEntries == 100)
   {
       printf("Number can't be inserted, array full\n");
       return numEntries;
   }

   //start from the end of the array and shift all the elements
   //larger than newValue to one position right
   //when this loop stops, variable i will point to one left of the
   //position of newValue

   int i=numEntries-1;
   while(i>=0 && myArray[i]>newValue)
   {
       myArray[i+1]=myArray[i];
       i--;
   }
   myArray[i+1]=newValue;

   //new size of array
   numEntries++;
   return numEntries;

}

//test function to check the program
void printArray(int myArray[], int numEntries)
{
   for(int i=0; i<numEntries; i++)
       printf("%d ", myArray[i]);
   printf("\n");
}

int main()
{
   int myArray[100];
   int numEntries = 0;
   //open file
   FILE* fp = fopen("filename.txt", "r");
   int newValue;
   //read numbers from file
   while(!feof(fp))
   {
       fscanf(fp,"%d", &newValue);
       numEntries = insertIntoSortedArray(myArray,numEntries,newValue);
       printArray(myArray,numEntries);
       if(numEntries==100)
           break;
   }
   //close file
   fclose(fp);

   return 0;
}

Output for the following input:

5 4 6 10 7 1 6 9 6