Exercise 3-5. Write the function itob(n,s,b) that converts the integer n into a base b character representation in the string s. In particular, itob(n,s,16) should produce in s a hexadecimal string. itob generalises itoa from base 10 to any base 2–36. The only change to the digit-extraction loop is replacing n % 10 with n …
Exercise 3-4. In a two’s complement number representation, our version of itoa does not handle the largest negative number, that is, the value of n equal to −(2wordsize−1). Explain why not. Modify it to print that value correctly, regardless of the machine on which it runs. This exercise has two parts: explain the bug, then …
How do you get system information from a C program? There are three portable-ish layers, and knowing which to use is the actual lesson: getenv() reads environment variables (pure standard C), system() runs a shell command like uname (standard C, but it launches a whole shell), and POSIX uname() fills a struct with OS name, …
To reverse a linked list in C, walk through the list with three pointers — prev, curr, and nxt — flipping each node’s next pointer to point backwards as you go. When curr reaches NULL you have finished, and prev is the new head. This iterative approach runs in O(n) time and O(1) space and …
C Program to Implement Numerical Integration (Trapezoidal / Rectangle Rule) Numerical integration approximates a definite integral by summing the areas of thin vertical slices under the curve. The rectangle rule divides the interval [a, b] into N equal strips and sums f(x) * width for each strip. Integration is used in engineering and science to …
Exercise 3-3. Write a function expand(s1,s2) that expands shorthand notations like a-z in the string s1 into the equivalent complete list abc…xyz in s2. Allow for letters or digits on either end of a range, and take care of cases like a-b-c and a-z0-9 and -a. Arrange that a leading or trailing – is taken …