solve(2996): implement solution using hash set

Author: kallydev

src/solutions/_2996_smallest_missing_integer_greater_than_sequential_prefix_sum.rs

@@ -0,0 +1,26 @@
+use std::collections::HashSet;
+
+use crate::solutions::Solution;
+
+impl Solution {
+    pub fn missing_integer(nums: Vec<i32>) -> i32 {
+        let prefix_len = 1 + nums
+            .windows(2)
+            .take_while(|pair| pair[1] == pair[0] + 1)
+            .count();
+
+        let prefix_sum = nums.iter().take(prefix_len).sum::<i32>();
+
+        let hash_set: HashSet<i32> = nums.iter().cloned().collect();
+
+        (prefix_sum..)
+            .find(|x| !hash_set.contains(x))
+            .unwrap_or(prefix_sum)
+    }
+}
+
+#[test]
+fn test() {
+    assert_eq!(Solution::missing_integer(vec![1, 2, 3, 2, 5]), 6);
+    assert_eq!(Solution::missing_integer(vec![3, 4, 5, 1, 12, 14, 13]), 15);
+}

src/solutions/mod.rs

@@ -6,6 +6,7 @@ pub mod _0027_remove_element;
 pub mod _0929_unique_email_addresses;
 pub mod _1848_minimum_distance_to_the_target_element;
 pub mod _2351_first_letter_to_appear_twice;
+pub mod _2996_smallest_missing_integer_greater_than_sequential_prefix_sum;
 pub mod _3046_split_the_array;
 pub mod _3151_special_array_i;
 pub mod _3174_clear_digits;