Vertical histogram of frequencies of characters in a given string using an example in C programming(c programming examples)(c program examples)

Vertical histogram of frequencies of characters in a given string using an example in C programming

This is an example in C language which is written on the base of basic C programming, if condition and for loop.

If you want to see this code with a perfect indentation, copy the code into "sublime text editor" and make sure that the type of code is set to 'c' at the bottom right of the window. After pasting the code press the command "ctrl+shift+P", you get a search box. Type "indentation" you get an option like this below the search box "Indentation: Reindent lines". Clink on that to get the code with indentation.

Keywords:- vertical histogram in c, vertical histogram of characters in c, program to print a vertical histogram of characters in c.


The program is as follows:

#include <stdio.h>
int main()
{
char string[1000],cc[100],c[100];
int i,j,k,check=0,max=0;
printf("enter any string\n");
gets(string);
for(i=0;string[i]!='\0';i++)
{
for(j=0;j<i;j++)
if(string[i]==string[j])
check++;
if(check==0)
{
cc[k]=string[i];
k++;
}
check=0;
}
cc[k]='\0';
for(i=0;i<k;i++)
{
for(j=0;string[j]!='\0';j++)
{
if(cc[i]==string[j])
check++;
}
c[i]=check;
check=0;
}
c[i]='\0';
for(i=0;cc[i]!='\0';i++)
printf("%c  %d\n",cc[i],c[i] );
for(i=0;c[i]!='\0';i++)
if(max<c[i])
max=c[i];
for(max=max;max>0;max--)
{
for(i=0;c[i]!='\0';i++)
{
if(max!=c[i])
printf("_");
if(max==c[i])
{
printf("*");
c[i]--;
}
}
printf("\n");
}
for(i=0;cc[i]!='\0';i++)
printf("%c",cc[i]);
return 0;
}


The output is as follows:

This is an example in C language which is written on the base of basic C programming, if condition and for loop.

Detailed explanation about the program:

ABOUT STDIO.H

STANDARD INPUT AND OUTPUT HEADER FILE

     'Stdio.h' is a header file. Header files are the files with an extension '.h' after the name of the file.  Header files are the set of defined functions in C source files. These defined functions are very helpful in compiling and execution of the code. Including of these header files is same as copying the functions in the code. But, using of predefined source files with header files is very flexible to understand and write the code. It also helps in debugging also. The following functions are written in the stdio.h file.

printf() :- This function is used to print whatever the user want to print.

scanf() :- This function is used to assign the input value given by the user into a variable or to an array.

getc() :- This function reads a character from the file.

gets() :- This function reads the entire line given by the user.

getchar() :- This function reads the character given by the user.

puts() :- This function prints the line on the output screen.

putchar() :- This function prints a character on the output screen.

clearerr() :- This function clears the error indicators.

--------------------------------------------------------------------------------------------------------------------------

char string[1000],cc[100],c[100];

     Declared three type of strings. The array 'char string[1000]' is used to hold the given input by the user. The array 'cc[100]' is used to store the unique characters in the given input string by the user.  The third array 'c[100]' is used to carry the number of occurrences of each unique character in the string.

 int i,j,k,check=0,max=0;

    We declared integer variables for some operations in the program.  i,j and k are used in for loop for iterations.  Especially the integer variable 'k' is used to know the number of unique characters and the size of the two arrays 'cc[100]' and 'c[100]'. The 'check' variable is used to count the number of occurrences of each unique character in the given string.  The variable 'max' is used to find the maximum number of occurrences among all the characters in the array.

printf("enter any string\n");

    It is the message to the user as a call to enter the input to print the vertical histogram of the individual unique characters in the string.

gets(string);

     This line is to store the given string input by the user into an array 'string[1000]'.

for(i=0;string[i]!='\0';i++)

   {

       for(j=0;j<i;j++)

           if(string[i]==string[j])

            check++;

        if(check==0)

        {

           cc[k]=string[i]; 

           k++; 

       }

       check=0;

   }

Here comes the for loop. The syntax of for loop is as bellow:

for(initiation;codition;increment/decrement)

{

          /*body of loop*/

}

Initiation: i=0

     

     According to arrays the address of each box of an array is addressed by a number. And the first box is addressed as 'string[0]' so, we take '0' as the initiation.

Condition: string[i]!='\0'

    The command gets() stores the each individual character into a box in an array. At the end of the last character, the array is filled with null character.  So, in the condition, we tell the computer to check whether iteration comes to an end or not. At the end, the for loop terminates and the execution carries on to the next line of the program.

Increment/Decrement: i++;

     To check each character stored in string[i] we use an increment of 'i' by one.  

 for(j=0;j<i;j++)

     Inside there is another for loop to check the character is repeated how many times previously.

 if(check==0)

        {

           cc[k]=string[i]; 

           k++; 

       }

If the character is not repeated previously the character is stored in the second array 'cc[100]'.

check=0;

After checking each character the variable is assigned by '0' for the next iteration.

  for(i=0;i<k;i++)

   {

       for(j=0;string[j]!='\0';j++)

       {

           if(cc[i]==string[j])

               check++;

       }

       c[i]=check;

       check=0;

   }

     This for loop is used to find the number of occurrences of each individual character in the given input string.

for(i=0;c[i]!='\0';i++)

       if(max<c[i])

           max=c[i];

       for(max=max;max>0;max--)

       {

           for(i=0;c[i]!='\0';i++)

           {

               if(max!=c[i])

                   printf("_");

               if(max==c[i])

               {

                   printf("*");

                   c[i]--;

               }

           }

           printf("\n");

       }

Here comes the major logic the entire program to print the histogram based on the repetition of the characters in the given string. First, we find the maximum number in the array 'c[100]' and then it prints the character '*' else it prints the character '_'. After completion of all the boxes in the array, it prints new line character '\n'. The max value is decreased by one every time it gets the new line character and the number value is also decresed after printing the character '*'.

for(i=0;cc[i]!='\0';i++)

           printf("%c",cc[i]);

At the end of the histogram, we print the unique characters in the string to represent that the line above each character represents how times it is repeated in the string.

C is a general-purpose programming language. It has been closely associated with the UNIX system where is was developed, since both the system and most of the programs that run on it are written in C. The language, however, is not tied to any one operating system or machine; and although it has been called a “system programming language” because it is useful for writing compilers and operating systems, it has been used equally well to write major programs in many different domains.(c programming examples)(c program examples)

Many of the important ideas of C stem from the language BCPL, developed by Martin Richards. The influence of BCPL on C proceeded indirectly through the language B, which was written by Ken Thompson in 1970 for the first UNIX system on the DEC PDP-7.(c programming examples)

BCPL and B are “typeless” languages. By contrast, C provides a variety of data types. The fundamental types are characters, and integers and floating point numbers of several sizes. In addition, there is a hierarchy of derived data types created with pointers, arrays, structures, and unions. Expressions are formed from operators and operands; any expression, including an assignment or a function call, can be a statement. Pointers provide for machine-independent address arithmetic.(c programming examples)(c program examples)

C provides the fundamental control-flow constructions required for well-structured programs: statement grouping, decision making (if-else), selecting one of a set of possible cases (switch), looping with the termination test at the top (while, for) or at the bottom (do), and early loop exit (break).(c programming examples)(c program examples)

Functions may return values of basic types, structures, unions, or pointers. Any function may be called recursively. Local variables are typically “automatic,” or created anew with each invocation. Function definitions may not be nested but variables may be declared in a block-structured fashion. The functions of a C program may exist I separate source files that are compiled separately. Variables may be internal to a function, external but know only within a single source file, or visible to the entire program.(c programming examples)(c program examples)

A preprocessing step performs macro substitution on program text, inclusion of other source files, conditional compilation.(c programming examples)(c program examples)

C  is a relatively “low level” language. This characterization is not pejorative; it simply means that C deals with the same sort of object that most computers do, namely characters, numbers, and addresses. These may be combined and moved about with the arithmetic and logical operators implemented by real machines.(c programming examples)(c program examples)

C provides no operations to deal directly with composite objects such as character strings, sets, lists, or arrays. There are no operations that manipulate an entire array or string, although structures may be copied as a unit. The language does not define any storage allocation facility other than static definition and the stack discipline provided by the local variables of functions; there is n heap or garbage collection. Finally, C itself provides no input/output facilities; there are no READ or WRITE statements, and no built-in file access methods. All of these higher-level mechanisms must be provided by explicitly called functions. Most C implementations have included a reasonably standard collection of such functions.(c programming examples)(c program examples)

next post:

Finding the power of a number from 0 up to its 10th power using a function in a C program