Given a list of numbers, return all groups of repeating consecutive numbers.

main.rs

/// Given a list of numbers, return all groups of repeating consecutive numbers.
///
/// Examples:
///
/// ```
/// > repeatedGroups([1, 2, 2, 4, 5])
/// [[2, 2]]
///
/// > repeatedGroups([1, 1, 0, 0, 8, 4, 4, 4, 3, 2, 1, 9, 9])
/// [[1, 1], [0, 0], [4, 4, 4], [9, 9]]
/// ```

fn main() {
    println!("Hello, world!");
}

fn repeated_groups(nums: Vec<isize>) -> Vec<Vec<isize>> {
    let mut i = 0;
    let mut j = 0;

    let mut res: Vec<Vec<isize>> = vec![];
    let mut curr: Vec<isize> = vec![];

    while j < nums.len() {
        if nums[i] != nums[j] {
            if curr.len() > 1 {
                res.push(curr);
            }

            i = j;
            j += 1;
            curr = vec![nums[i]];
            continue;
        }

        curr.push(nums[i]);
        j += 1;
    }

    // If the last iteration is a repeated group, the loop exits before appending
    // the last group to the results, so we check here for what the last group was
    // and add it to the result if need be.
    if curr.len() > 1 {
        res.push(curr);
    }

    res
}

#[cfg(test)]
mod tests {
    use super::*;

    #[test]
    fn test_repeated_groups() {
        let nums = vec![1, 2, 2, 4, 5];
        assert_eq!(vec![vec![2, 2]], repeated_groups(nums));

        let nums = vec![1, 1, 0, 0, 8, 4, 4, 4, 3, 2, 1, 9, 9];
        assert_eq!(
            vec![vec![1, 1], vec![0, 0], vec![4, 4, 4], vec![9, 9]],
            repeated_groups(nums)
        );
    }
}