Rust Program: Print Fibonacci Sequence up to Specified Terms

Rust Functions and Control Flow: Exercise-8 with Solution

Write a Rust program that defines a function to print the Fibonacci sequence up to a specified number of terms.

Sample Solution:

Rust Code:

// Define a function named 'print_fibonacci_sequence' that takes a number 'n' as input and prints the Fibonacci sequence up to 'n' terms
fn print_fibonacci_sequence(n: usize) {
    let mut fib = (0, 1); // Initialize a tuple to store the Fibonacci sequence (F(n-1), F(n))
    
    println!("Fibonacci sequence up to {} terms:", n);
    
    if n >= 1 {
        println!("{}", fib.0); // Print the first Fibonacci number (0)
    }
    if n >= 2 {
        println!("{}", fib.1); // Print the second Fibonacci number (1)
    }

    for _ in 3..=n {
        let next_fib = fib.0 + fib.1; // Calculate the next Fibonacci number
        println!("{}", next_fib); // Print the next Fibonacci number
        fib = (fib.1, next_fib); // Update the tuple to store the next Fibonacci number
    }
}

fn main() {
    let num_terms = 10; // Define the number of terms in the Fibonacci sequence

    // Call the 'print_fibonacci_sequence' function with the specified number of terms
    print_fibonacci_sequence(num_terms);
}

Output:

Fibonacci sequence up to 10 terms:
0
1
1
2
3
5
8
13
21
34

Explanation:

Here's a brief explanation of the above Rust code:

• fn print_fibonacci_sequence(n: usize) { ... }: This is a function named "print_fibonacci_sequence()" that takes a number 'n' as input (of type 'usize', an unsigned integer) and prints the Fibonacci sequence up to 'n' terms.
• Inside the function:
• We initialize a tuple 'fib' to store the Fibonacci sequence, starting with the initial values (0, 1).
• We print the message indicating the number of terms.
• We handle the base cases (first two Fibonacci numbers) separately:
• If 'n' is greater than or equal to 1, we print the first Fibonacci number (0).
• If 'n' is greater than or equal to 2, we print the second Fibonacci number (1).
• We then iterate from the 3rd term to the nth term, calculating and printing each Fibonacci number in the sequence.
• In the main function,
• We define the number of terms in the Fibonacci sequence ('num_terms').
• We call the "print_fibonacci_sequence()" function with the specified number of terms.

Rust Code Editor:

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