Program 261: Program to print Frequency of digits in an Array

Program 261: Program to print Frequency of digits in an Array

#include<stdio.h>
main()
{
 int i,n,num,k,frequency[10],flag=0;
 for(i=0;i<10;i++)
 {
  frequency[i]=0;
 }
 printf("Enter number of elements in an array\n");
 scanf("%d",&n);
 int a[n];
 printf("Enter numbers\n");
 for(i=0;i<n;i++)
 {
  scanf("%d",&a[i]);
  //for incrementing occured number
  num=a[i];
  while(num>0)
  {
   k=num%10;
   frequency[k]++;
   num=num/10;
  }
 }
 for(i=0;i<10;i++)
 {
  if(frequency[i]!=0)
  {
   flag=1;
   printf("%d occured %d times\n",i,frequency[i]);
  }
 }
 if(flag==0)
 {
  printf("No elements repeated\n");
 }
} 

To know the frequency of each character in senetence

Explanation:

1. The Program Starts with intializing
   • i,k,num→ Temporary variables
     
   • n→ To store number of elements
   • frequency → To store frequency of digits
   • flag→ used as boolean variable
   • a → To store Array elements

2. for(i=0;i<10;i++)
    {
     frequency[i]=0;
    }

   By defaults all the frequency of digits are assigned to zero like frequency[0],frequency[1]...=0

3.  printf("Enter number of elements in an array\n");
    scanf("%d",&n);

   To Take how many elements user is going to enter as input. 

4. for(i=0;i<n;i++)
    {
     scanf("%d",&a[i]);
     //for incrementing occured number
     num=a[i];
     while(num>0)
     {
      k=num%10;
      frequency[k]++;
      num=num/10;
     }
    }

   While taking input we are storing the number in dummy variable 'num' and splitting each digit using while loop from which we are calculating frequency of digits.For Example:
   
   • We Entered 2556 then, num=256.Lets run the while loop and check how its doing this
     • Iteration 1: As num=2556 and 2556>0,which is true so while loop executes
       • k=2556%10=6
       • frequency[k]++→ frequency[6]++→ frequency[6]=1
       • num=num/10→ 2556/10=255,So num=255 Now.
       • Finally frequency[6]=1,num=255
     • Iteration 2: num=255 and 255>0,which is true so while loop executes
       • k=255%10=5
       • frequency[k]++→ frequency[5]++→ frequency[5]=1
       • num=num/10→ 255/10=25,So num=25.
       • Finally frequency[6]=1,frequency[5]=1,num=25
     • Iteration 3: num=2 and 2>0,which is true so while loop executes
       • k=2%10=2
       • frequency[k]++→ frequency[2]++→ frequency[2]=1
       • num=num/10→ 2/10=0,So num=0.(remember num is integer not float)
       • Finally frequency[6]=1,frequency[5]=2,frequency[2]=1,num=0
     • Iteration 3: num=0 and 0>0,which is false so while loop terminates
     • Finally we got frequency of first Number 2556 and the frequency is
       frequency[6]=1,frequency[5]=2,frequency[2]=1

5. for(i=0;i<10;i++)
    {
     if(frequency[i]!=0)
     {
      flag=1;
      printf("%d occured %d times\n",i,frequency[i]);
     }
    }

   Finally if frequency of a particular digit is not zero (which was assigned to zero by default) is printed as 6 occured 1 times,5 occured 2 times,2 occured 1 times

Output: