leetcode: Add merge array

leetcode/0088.merge-sorted-array/Cargo.toml

@@ -0,0 +1,7 @@
+[package]
+name = "lc-0088-merge-sorted-array"
+version = "0.1.0"
+edition = "2021"
+publish = false
+
+[dependencies]

leetcode/0088.merge-sorted-array/src/main.rs

@@ -0,0 +1,92 @@
+// Copyright (c) 2023 Xu Shaohua <[email protected]>. All rights reserved.
+// Use of this source is governed by General Public License that can be
+// found in the LICENSE file.
+
+pub fn merge(nums1: &mut Vec<i32>, m: i32, nums2: &[i32], n: i32) {
+    let m = m as usize;
+    let n = n as usize;
+    assert_eq!(nums1.len(), m + n);
+
+    if m == 0 {
+        for (index, num) in nums2.iter().enumerate() {
+            nums1[index] = *num;
+        }
+        return;
+    }
+    if n == 0 {
+        return;
+    }
+
+    // source indexes.
+    let mut i = m - 1;
+    let mut j = n - 1;
+    // target index
+    let mut k = m + n - 1;
+
+    loop {
+        if nums1[i] >= nums2[j] {
+            nums1[k] = nums1[i];
+            if i == 0 {
+                break;
+            }
+            i -= 1;
+        } else {
+            nums1[k] = nums2[j];
+            if j == 0 {
+                return;
+            }
+            j -= 1;
+        }
+        k -= 1;
+    }
+
+    loop {
+        nums1[j] = nums2[j];
+        if j == 0 {
+            break;
+        }
+        j -= 1;
+    }
+}
+
+fn main() {
+    let mut nums1 = vec![1, 2, 3, 0, 0, 0];
+    let m = 3;
+    let nums2 = vec![2, 5, 6];
+    let n = 3;
+    let expected_out = vec![1, 2, 2, 3, 5, 6];
+    merge(&mut nums1, m, &nums2, n);
+    assert_eq!(nums1, expected_out);
+
+    let mut nums1 = vec![1];
+    let m = 1;
+    let nums2 = vec![];
+    let n = 0;
+    let expected_out = vec![1];
+    merge(&mut nums1, m, &nums2, n);
+    assert_eq!(nums1, expected_out);
+
+    let mut nums1 = vec![0];
+    let m = 0;
+    let nums2 = vec![1];
+    let n = 1;
+    let expected_out = vec![1];
+    merge(&mut nums1, m, &nums2, n);
+    assert_eq!(nums1, expected_out);
+
+    let mut nums1 = vec![21, 22, 23, 0, 0, 0];
+    let m = 3;
+    let nums2 = vec![2, 5, 6];
+    let n = 3;
+    let expected_out = vec![2, 5, 6, 21, 22, 23];
+    merge(&mut nums1, m, &nums2, n);
+    assert_eq!(nums1, expected_out);
+
+    let mut nums1 = vec![21, 22, 23, 0, 0, 0];
+    let m = 3;
+    let nums2 = vec![32, 35, 36];
+    let n = 3;
+    let expected_out = vec![21, 22, 23, 32, 35, 36];
+    merge(&mut nums1, m, &nums2, n);
+    assert_eq!(nums1, expected_out);
+}