1909. Remove One Element to Make the Array Strictly Increasing: AC

Author: tan-wei

src/solution/mod.rs

@@ -1438,3 +1438,4 @@ mod s1903_largest_odd_number_in_string;
 mod s1904_the_number_of_full_rounds_you_have_played;
 mod s1905_count_sub_islands;
 mod s1906_minimum_absolute_difference_queries;
+mod s1909_remove_one_element_to_make_the_array_strictly_increasing;

src/solution/s1909_remove_one_element_to_make_the_array_strictly_increasing.rs

@@ -0,0 +1,100 @@
+/**
+ * [1909] Remove One Element to Make the Array Strictly Increasing
+ *
+ * Given a 0-indexed integer array nums, return true if it can be made strictly increasing after removing exactly one element, or false otherwise. If the array is already strictly increasing, return true.
+ * The array nums is strictly increasing if nums[i - 1] < nums[i] for each index (1 <= i < nums.length).
+ *  
+ * Example 1:
+ *
+ * Input: nums = [1,2,<u>10</u>,5,7]
+ * Output: true
+ * Explanation: By removing 10 at index 2 from nums, it becomes [1,2,5,7].
+ * [1,2,5,7] is strictly increasing, so return true.
+ *
+ * Example 2:
+ *
+ * Input: nums = [2,3,1,2]
+ * Output: false
+ * Explanation:
+ * [3,1,2] is the result of removing the element at index 0.
+ * [2,1,2] is the result of removing the element at index 1.
+ * [2,3,2] is the result of removing the element at index 2.
+ * [2,3,1] is the result of removing the element at index 3.
+ * No resulting array is strictly increasing, so return false.
+ * Example 3:
+ *
+ * Input: nums = [1,1,1]
+ * Output: false
+ * Explanation: The result of removing any element is [1,1].
+ * [1,1] is not strictly increasing, so return false.
+ *
+ *  
+ * Constraints:
+ *
+ * 	2 <= nums.length <= 1000
+ * 	1 <= nums[i] <= 1000
+ *
+ */
+pub struct Solution {}
+
+// problem: https://leetcode.com/problems/remove-one-element-to-make-the-array-strictly-increasing/
+// discuss: https://leetcode.com/problems/remove-one-element-to-make-the-array-strictly-increasing/discuss/?currentPage=1&orderBy=most_votes&query=
+
+// submission codes start here
+
+impl Solution {
+    pub fn can_be_increasing(nums: Vec<i32>) -> bool {
+        let (mut is_dropped, mut prev_min) = (false, nums[0]);
+
+        for (i, &num) in nums.iter().enumerate().skip(1) {
+            match num <= prev_min {
+                true if is_dropped => return false,
+                true => {
+                    is_dropped = true;
+                    if i == 1 || num > nums[i - 2] {
+                        prev_min = num;
+                    }
+                }
+                false => {
+                    prev_min = num;
+                }
+            };
+        }
+
+        true
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_1909_example_1() {
+        let nums = vec![1, 2, 10, 5, 7];
+
+        let result = true;
+
+        assert_eq!(Solution::can_be_increasing(nums), result);
+    }
+
+    #[test]
+    fn test_1909_example_2() {
+        let nums = vec![2, 3, 1, 2];
+
+        let result = false;
+
+        assert_eq!(Solution::can_be_increasing(nums), result);
+    }
+
+    #[test]
+    fn test_1909_example_3() {
+        let nums = vec![1, 1, 1];
+
+        let result = false;
+
+        assert_eq!(Solution::can_be_increasing(nums), result);
+    }
+}