add solution

Author: jtr109

merge_sorted_array/src/lib.rs

@@ -1,7 +1,81 @@
+/*!
+ * 88. Merge Sorted Array
+ *
+ * * [Problem link](https://leetcode.com/problems/merge-sorted-array/)
+ */
+
+#![allow(dead_code)]
+
+struct Solution {}
+
+// ----------------------------------------------------------------------------
+
+impl Solution {
+    pub fn merge(nums1: &mut Vec<i32>, m: i32, nums2: &mut Vec<i32>, n: i32) {
+        let (mut i, mut length) = (0 as usize, m as usize);
+        let mut j = 0 as usize;
+        while j < n as usize {
+            let n2 = nums2[j];
+            if i >= length {
+                // if all numbers in nums1 spent
+                nums1[i] = n2;
+                i += 1;
+                length += 1;
+                j += 1;
+                continue;
+            }
+            if nums1[i] <= n2 {
+                i += 1;
+            } else {
+                // insert n2
+                let mut k = length;
+                while k > i {
+                    nums1[k] = nums1[k - 1];
+                    k -= 1;
+                }
+                nums1[i] = n2;
+                i += 1;
+                length += 1;
+                j += 1;
+            }
+        }
+    }
+}
+
 #[cfg(test)]
 mod tests {
+    use super::*;
+
+    #[test]
+    fn test_example() {
+        let mut nums1 = vec![1, 2, 3, 0, 0, 0];
+        let m = 3;
+        let mut nums2 = vec![2, 5, 6];
+        let n = 3;
+        Solution::merge(&mut nums1, m, &mut nums2, n);
+        let expected = vec![1, 2, 2, 3, 5, 6];
+        assert_eq!(nums1, expected);
+    }
+
+    #[test]
+    fn test_example2() {
+        let mut nums1 = vec![0];
+        let m = 0;
+        let mut nums2 = vec![1];
+        let n = 1;
+        Solution::merge(&mut nums1, m, &mut nums2, n);
+        let expected = vec![1];
+        assert_eq!(nums1, expected);
+    }
+
     #[test]
-    fn it_works() {
-        assert_eq!(2 + 2, 4);
+    fn test_example3() {
+        let mut nums1 = vec![2, 0];
+        let m = 1;
+        let mut nums2 = vec![1];
+        let n = 1;
+        Solution::merge(&mut nums1, m, &mut nums2, n);
+        let expected = vec![1, 2];
+        assert_eq!(nums1, expected);
     }
 }