From 4812419687523d92a7d536f352b05264b3013f30 Mon Sep 17 00:00:00 2001
From: Justin Sexton <justinsexton.dev@gmail.com>
Date: Sat, 23 Dec 2023 02:00:47 -0600
Subject: [PATCH] Added kth largest element solution

---
 README.md                           |  1 +
 src/leetcode/kth_largest_element.rs | 28 ++++++++++++++++++++++++++++
 src/leetcode/mod.rs                 |  1 +
 3 files changed, 30 insertions(+)
 create mode 100644 src/leetcode/kth_largest_element.rs

diff --git a/README.md b/README.md
index 639444a..6de7520 100644
--- a/README.md
+++ b/README.md
@@ -104,6 +104,7 @@ other languages.
 - Authentication Manager (https://leetcode.com/problems/design-authentication-manager/)
 - Best Time to Buy and Sell Stock (https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii)
 - Longest Substring Without Repeating Characters (https://leetcode.com/problems/longest-substring-without-repeating-characters/)
+- Kth Largest Element (https://leetcode.com/problems/kth-largest-element-in-an-array/)
 
 ### Other
 
diff --git a/src/leetcode/kth_largest_element.rs b/src/leetcode/kth_largest_element.rs
new file mode 100644
index 0000000..b40e2a5
--- /dev/null
+++ b/src/leetcode/kth_largest_element.rs
@@ -0,0 +1,28 @@
+use std::cmp::Reverse;
+use std::collections::BinaryHeap;
+
+pub fn find_kth_largest(numbers: Vec<i32>, k: i32) -> i32 {
+    let k = k as usize;
+    let mut heap: BinaryHeap<_> = numbers[..k].iter().map(Reverse).collect();
+    for number in &numbers[k..] {
+        heap.push(Reverse(number));
+        heap.pop();
+    }
+    *heap.peek().unwrap().0
+}
+
+#[cfg(test)]
+mod tests {
+    use test_case::test_case;
+
+    use crate::leetcode::kth_largest_element::find_kth_largest;
+
+    #[test_case(&[1, 2, 3, 4], 2, 3)]
+    #[test_case(&[1, 1, 3, 4, 5, 6], 5, 1)]
+    #[test_case(&[1, 2, 3], 1, 3)]
+    #[test_case(&[15, 5, 1, 3, 4, 5, 6, 9, 11], 2, 11)]
+    fn should_return_kth_largest_element(numbers: &[i32], k: i32, expected: i32) {
+        let result = find_kth_largest(numbers.to_vec(), k);
+        assert_eq!(result, expected);
+    }
+}
diff --git a/src/leetcode/mod.rs b/src/leetcode/mod.rs
index f510f19..8ffa4d3 100644
--- a/src/leetcode/mod.rs
+++ b/src/leetcode/mod.rs
@@ -19,3 +19,4 @@ mod climb_stairs;
 mod longest_subtsring;
 mod largest_odd_number;
 mod number_of_strings;
+mod kth_largest_element;