1558. Minimum Numbers of Function Calls to Make Target Array: AC

Author: tan-wei

src/solution/mod.rs

@@ -1174,3 +1174,4 @@ mod s1552_magnetic_force_between_two_balls;
 mod s1553_minimum_number_of_days_to_eat_n_oranges;
 mod s1556_thousand_separator;
 mod s1557_minimum_number_of_vertices_to_reach_all_nodes;
+mod s1558_minimum_numbers_of_function_calls_to_make_target_array;

src/solution/s1558_minimum_numbers_of_function_calls_to_make_target_array.rs

@@ -0,0 +1,102 @@
+/**
+ * [1558] Minimum Numbers of Function Calls to Make Target Array
+ *
+ * You are given an integer array nums. You have an integer array arr of the same length with all values set to 0 initially. You also have the following modify function:
+ * <img alt="" src="https://assets.leetcode.com/uploads/2020/07/10/sample_2_1887.png" style="width: 573px; height: 294px;" />
+ * You want to use the modify function to convert arr to nums using the minimum number of calls.
+ * Return the minimum number of function calls to make nums from arr.
+ * The test cases are generated so that the answer fits in a 32-bit signed integer.
+ *  
+ * Example 1:
+ *
+ * Input: nums = [1,5]
+ * Output: 5
+ * Explanation: Increment by 1 (second element): [0, 0] to get [0, 1] (1 operation).
+ * Double all the elements: [0, 1] -> [0, 2] -> [0, 4] (2 operations).
+ * Increment by 1 (both elements)  [0, 4] -> [1, 4] -> [1, 5] (2 operations).
+ * Total of operations: 1 + 2 + 2 = 5.
+ *
+ * Example 2:
+ *
+ * Input: nums = [2,2]
+ * Output: 3
+ * Explanation: Increment by 1 (both elements) [0, 0] -> [0, 1] -> [1, 1] (2 operations).
+ * Double all the elements: [1, 1] -> [2, 2] (1 operation).
+ * Total of operations: 2 + 1 = 3.
+ *
+ * Example 3:
+ *
+ * Input: nums = [4,2,5]
+ * Output: 6
+ * Explanation: (initial)[0,0,0] -> [1,0,0] -> [1,0,1] -> [2,0,2] -> [2,1,2] -> [4,2,4] -> [4,2,5](nums).
+ *
+ *  
+ * Constraints:
+ *
+ * 	1 <= nums.length <= 10^5
+ * 	0 <= nums[i] <= 10^9
+ *
+ */
+pub struct Solution {}
+
+// problem: https://leetcode.com/problems/minimum-numbers-of-function-calls-to-make-target-array/
+// discuss: https://leetcode.com/problems/minimum-numbers-of-function-calls-to-make-target-array/discuss/?currentPage=1&orderBy=most_votes&query=
+
+// submission codes start here
+
+impl Solution {
+    pub fn min_operations(nums: Vec<i32>) -> i32 {
+        let mut result = 0;
+        let mut max = 0;
+        for &num in nums.iter() {
+            let mut cv = num;
+            let mut temp = 0;
+            while cv > 0 {
+                if cv % 2 == 0 {
+                    cv /= 2;
+                    temp += 1;
+                } else {
+                    cv -= 1;
+                    result += 1;
+                }
+            }
+            max = max.max(temp);
+        }
+
+        result + max
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_1558_example_1() {
+        let nums = vec![1, 5];
+
+        let result = 5;
+
+        assert_eq!(Solution::min_operations(nums), result);
+    }
+
+    #[test]
+    fn test_1558_example_2() {
+        let nums = vec![2, 2];
+
+        let result = 3;
+
+        assert_eq!(Solution::min_operations(nums), result);
+    }
+
+    #[test]
+    fn test_1558_example_3() {
+        let nums = vec![4, 2, 5];
+
+        let result = 6;
+
+        assert_eq!(Solution::min_operations(nums), result);
+    }
+}