20240408 Finished

src/problem/mod.rs

@@ -95,4 +95,5 @@ mod p88_merge_sorted_array;
 mod p26_remove_duplicates_from_sorted_array;
 mod p27_remove_element;
 mod p80_remove_duplicates_from_sorted_array_ii;
-mod p169_majority_element;
+mod p169_majority_element;
+mod p189_rotate_array;

src/problem/p189_rotate_array.rs

@@ -0,0 +1,44 @@
+/**
+ * [189] Rotate Array
+ */
+pub struct Solution {}
+
+// submission codes start here
+
+impl Solution {
+    pub fn rotate(nums: &mut Vec<i32>, k: i32) {
+        let k = (k as usize) % nums.len();
+
+        if k == 0 {
+            return;
+        }
+
+        let mut temp = Vec::with_capacity(k);
+
+        for i in (nums.len() - k)..nums.len() {
+            temp.push(nums[i]);
+        }
+
+        for i in (0..(nums.len() - k)).rev() {
+            nums[i + k] = nums[i];
+        }
+
+        for i in 0..k {
+            nums[i] = temp[i];
+        }
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_189() {
+        let mut array = vec![1, 2, 3, 4, 5, 6, 7];
+        Solution::rotate(&mut array, 3);
+        assert_eq!(vec![5, 6, 7, 1, 2, 3, 4], array);
+    }
+}