GATE CS 2004 Q33 — Programming in C

Let's trace the execution of the given C program segment step-by-step:

1. The string pointer s points to the string literal "string".
2. The length of the string s is calculated using strlen(s), which is 6 (excluding the null terminator '\0').
3. The characters of s are indexed from 0 to 6 as follows:
   • s[0] = 's', s[1] = 't', s[2] = 'r', s[3] = 'i', s[4] = 'n', s[5] = 'g'
   • s[6] = '\0' (the null terminator)
4. The loop runs for $i = 0$ to $i < 6$ ($i = 0, 1, 2, 3, 4, 5$):
   • For $i = 0$:
     p[0] = s[6 - 0] = s[6] = '\0'
   • For $i = 1$:
     p[1] = s[5] = 'g'
   • For $i = 2$:
     p[2] = s[4] = 'n'
   • For $i = 3$:
     p[3] = s[3] = 'i'
   • For $i = 4$:
     p[4] = s[2] = 'r'
   • For $i = 5$:
     p[5] = s[1] = 't'

After the loop finishes, the array p contains {'\0', 'g', 'n', 'i', 'r', 't', ...}.

When printf("%s", p) is called, it starts printing characters from the beginning of the array p until it encounters the null character ('\0'). Since the very first element p[0] is '\0', the printing terminates immediately, and no output is printed.

Therefore, the correct option is D.