Introduction to Problem Solving with C

Introduction to Problem Solving

• This course aims to teach students how to solve problems through programming.
• Students will learn to develop logic-building skills.
• The course will use the C programming language.

Course Outcomes

• CO1: Remember the concepts related to fundamentals of C language, to draw flocharts and write algorithms/pseudocode.
• CO2: Understand how to execute and debug programs in C.
• CO3: Apply various constructs, loops, and functions to solve mathematical and scientific problems.
• CO4: Analyze dynamic memory behavior through the use of pointers.
• CO5: Design and develop modular programs for real-world problems using control and selection structures.

Assessment Pattern

• Theory:
  • Continuous Internal Assessment (CAE): 40 Marks
  • Semester End Examination (SEE): 60 Marks
• Practical:
  • Continuous Internal Assessment (CAE): 60 Marks
  • Semester End Examination (SEE): 40 Marks

String Definition

• A string in C is an array of characters terminated with a null character (\0).
• The null character indicates the end of the string.
• Strings are enclosed in double quotes (").
• Characters are enclosed in single quotes (').

Initialization of String

• Example: char string[] = "Hello";

Memory Representation of String

• When a string is declared, the compiler automatically allocates the memory space needed to store the null character (\0) at the end.
• Example:

  • For the string char string[] = "Hello";, the memory space would be:

    • H
    • e
    • l
    • l
    • o
    • \0

String Input and Output Functions

• scanf() Function:
  • Can be used to read string input from the terminal.
  • Uses the %s format specifier.
  • Terminates input on encountering the first whitespace.
• gets() Function:
  • Reads a line of string input from the terminal.
• puts() Function:
  • Displays a string.

Examples

• Example 1: gets() and puts() Functions:

  • #include <stdio.h>
  • int main() {
    • char string[100];
    • printf ("Enter your name: ");
    • gets(string);
    • printf ("Name: ");
    • puts(string);
    • return 0;
  • }

• Example 2: Concatenating Two Strings

  • #include <stdio.h>
  • int main() {
    • char s1[] = "programming ", s2[] = "is awesome";
    • int length = 0, j;
    • while (s1[length] != '\0'){
      • ++length;
    • }
    • for (j = 0; s2[j] != '\0'; ++j, ++length) {
      • s1[length] = s2[j];
    • }
    • s1[length] = '\0';
    • printf("After concatenation: ");
    • puts(s1);
    • return 0;
  • }

Summary

• Strings in C are arrays of characters ending with a null character (\0).
• Use gets() and puts() functions for input and output of strings.

Frequently Asked Questions

• Write a C program to count the number of lines, words, and characters in a given text.
• Write a C program to print all vowel and consonant characters separately.
• Write a C program to count the uppercase, lowercase, and special characters in a string.
• Write a C program to print the following pattern:
  • H
  • He
  • Hel
  • Hell
  • Hello

Quiz

• What is the format specifier used to print a string or character array in the printf or scanf function?

  • %c
  • %C
  • %s
  • %w

• What is the output of the following C program with strings?

  • int main() {
    • char ary[]="Discovery Channel";
    • printf("%s",ary);
    • return 0;
  • }
  • A) D
  • B) Discovery Channel
  • C) Discovery
  • D) Compiler Error

• What is the output of the following C program with strings?

  • int main() {
    • char str[]={'g','l','o','b','e'};
    • printf("%s",str);
    • return 0;
  • }
  • A) g
  • B) globe
  • C) globe\0
  • D) None of the above

• What is the output of the following C program?

  • int main() {
    • int str[]={'g','l','o','b','y'};
    • printf("A%c ",str);
    • printf("A%s ",str);
    • printf("A%c ",str);
    • return 0;
  • }
  • A) A A A
  • B) A Ag Ag
  • C) Arandomchar Ag Ag
  • D) Compiler error

Book Reference

• Thareja, R. (2014). Programming in C (2nd ed.).
• Zed, A.

This quiz evaluates students' understanding of problem-solving techniques using the C programming language. It covers fundamentals such as logic-building, algorithm design, and dynamic memory management through pointers. Students will also learn to effectively debug and develop modular programs for real-world applications.