GATE 2024 CS (CS1) – Question 57

Operating System · System Calls, Processes, Threads and IPC · 2 marks · Numerical answer

Consider the code:

int x = 3;
while (x > 0) {
    fork();
    printf("hello");
    wait(NULL);
    x--;
}

The total number of times the printf statement is executed is _______

Practise this question in The GATE Grind →

Show answer and explanation

Correct answer: 14

Explanation

Let f(x) be prints for a process with counter x: after fork, both parent and child print once and then continue with x−1, so f(x)=2(1+f(x−1)) with f(0)=0. f(1)=2, f(2)=6, f(3)=14.