Practical Examples

Below are small, practical snippets you can copy into a file and run.

Factorial (iterative)

fn factorial(n: i32) -> i32 {
    if n <= 1 {
        return 1;
    }
    let result: i32 = 1;
    let i := 2;
    while i <= n {
        result = result * i;
        i += 1;
    }
    return result;
}

Fibonacci (iterative)

fn fib(n: i32) -> i32 {
    if n <= 1 {
        return n;
    }
    let a := 0;
    let b := 1;
    for _ in 2..=n {
        let next := a + b;
        a = b;
        b = next;
    }
    return b;
}

Greatest Common Divisor (Euclid)

fn gcd(a: i32, b: i32) -> i32 {
    let x := a;
    let y := b;
    while y != 0 {
        let tmp := y;
        y = x % y;
        x = tmp;
    }
    return x;
}

Binary Search (sorted array)

fn binary_search(nums: []i32, target: i32) -> i32 {
    let left := 0;
    let right := len(nums) - 1;
    while left <= right {
        let mid := ((left + right) / 2) as i32;
        let val := nums[mid];
        if val == target {
            return mid;
        }
        if val < target {
            left = mid + 1;
        } else {
            right = mid - 1;
        }
    }
    return -1;
}

Bubble Sort (in-place)

fn bubble_sort(nums: []i32) {
    let n := len(nums);
    let i := 0;
    while i < n {
        let j := 0;
        while j + 1 < n - i {
            if nums[j] > nums[j + 1] {
                let tmp := nums[j];
                nums[j] = nums[j + 1];
                nums[j + 1] = tmp;
            }
            j += 1;
        }
        i += 1;
    }
}

Example Program

run

import "std/io";


fn factorial(n: i32) -> i32 {
    if n <= 1 {
        return 1;
    }
    let result: i32 = 1;
    let i := 2;
    while i <= n {
        result = result * i;
        i += 1;
    }
    return result;
}


fn fib(n: i32) -> i32 {
    if n <= 1 {
        return n;
    }
    let a := 0;
    let b := 1;
    for _ in 2..=n {
        let next := a + b;
        a = b;
        b = next;
    }
    return b;
}


fn gcd(a: i32, b: i32) -> i32 {
    let x := a;
    let y := b;
    while y != 0 {
        let tmp := y;
        y = x % y;
        x = tmp;
    }
    return x;
}


fn binary_search(nums: []i32, target: i32) -> i32 {
    let left := 0;
    let right := len(nums) - 1;
    while left <= right {
        let mid := ((left + right) / 2) as i32;
        let val := nums[mid];
        if val == target {
            return mid;
        }
        if val < target {
            left = mid + 1;
        } else {
            right = mid - 1;
        }
    }
    return -1;
}


fn bubble_sort(nums: &mut []i32) {
    let n := len(nums);
    let i := 0;
    while i < n {
        let j := 0;
        while j + 1 < n - i {
            if nums[j] > nums[j + 1] {
                let tmp := nums[j];
                nums[j] = nums[j + 1];
                nums[j + 1] = tmp;
            }
            j += 1;
        }
        i += 1;
    }
}


fn main() {
    io::Println(factorial(6)); // 720
    io::Println(fib(10));      // 55
    io::Println(gcd(84, 30));  // 6


    let nums := [9, 4, 1, 7, 3, 8, 2, 6, 5];
    bubble_sort(&mut nums);
    io::Println(nums[0]);      // 1
    io::Println(nums[8]);      // 9


    let idx := binary_search(nums, 7);
    io::Println(idx);          // 6
}