n0088_merge_sorted_array.rs

/**
 * [88] Merge Sorted Array
 *
 * Given two sorted integer arrays nums1 and nums2, merge nums2 into nums1 as one sorted array.
 * 
 * Note:
 * 
 * 
 * 	The number of elements initialized in nums1 and nums2 are m and n respectively.
 * 	You may assume that nums1 has enough space (size that is greater or equal to m + n) to hold additional elements from nums2.
 * 
 * 
 * Example:
 * 
 * 
 * Input:
 * nums1 = [1,2,3,0,0,0], m = 3
 * nums2 = [2,5,6],       n = 3
 * 
 * Output: [1,2,2,3,5,6]
 * 
 * 
 */
pub struct Solution {}

// submission codes start here

impl Solution {
    pub fn merge(nums1: &mut Vec<i32>, m: i32, nums2: &mut Vec<i32>, n: i32) {
        let mut i = m - 1;
        let mut j = n - 1;
        let mut z = m + n - 1;
        while z >= 0 {
            if i >= 0 && (j < 0 || nums1[i as usize] >= nums2[j as usize]) {
                nums1[z as usize] = nums1[i as usize];
                i -= 1;
            } else {
                nums1[z as usize] = nums2[j as usize];
                j -= 1;
            }
            z -= 1;
        }
    }
}

// submission codes end

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

    #[test]
    fn test_88() {
        let mut vec1 = vec![1,2,3,0,0,0];
        let mut vec2 = vec![2,5,6];
        Solution::merge(&mut vec1, 3, &mut vec2, 3);
        assert_eq!(
            vec1,
            vec![1,2,2,3,5,6]
        );

        let mut vec1 = vec![1,2,3];
        let mut vec2 = vec![];
        Solution::merge(&mut vec1, 3, &mut vec2, 0);
        assert_eq!(
            vec1,
            vec![1,2,3]
        );

        let mut vec1 = vec![0,0,0];
        let mut vec2 = vec![1,2,3];
        Solution::merge(&mut vec1, 0, &mut vec2, 3);
        assert_eq!(
            vec1,
            vec![1,2,3]
        );
    }
}