From e0fbca7ff9b2f496d07c1715363d7646052ea966 Mon Sep 17 00:00:00 2001
From: EFanZh <efanzh@gmail.com>
Date: Wed, 11 Dec 2024 22:57:39 +0800
Subject: [PATCH] Add problem 2358: Maximum Number of Groups Entering a
 Competition

---
 src/lib.rs                                    |  1 +
 .../mod.rs                                    | 18 +++++++++
 .../newtons_method.rs                         | 37 +++++++++++++++++++
 3 files changed, 56 insertions(+)
 create mode 100644 src/problem_2358_maximum_number_of_groups_entering_a_competition/mod.rs
 create mode 100644 src/problem_2358_maximum_number_of_groups_entering_a_competition/newtons_method.rs

diff --git a/src/lib.rs b/src/lib.rs
index b97ecadf..91e9412c 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1749,6 +1749,7 @@ pub mod problem_2351_first_letter_to_appear_twice;
 pub mod problem_2352_equal_row_and_column_pairs;
 pub mod problem_2353_design_a_food_rating_system;
 pub mod problem_2357_make_array_zero_by_subtracting_equal_amounts;
+pub mod problem_2358_maximum_number_of_groups_entering_a_competition;
 
 #[cfg(test)]
 mod test_utilities;
diff --git a/src/problem_2358_maximum_number_of_groups_entering_a_competition/mod.rs b/src/problem_2358_maximum_number_of_groups_entering_a_competition/mod.rs
new file mode 100644
index 00000000..cc7d8106
--- /dev/null
+++ b/src/problem_2358_maximum_number_of_groups_entering_a_competition/mod.rs
@@ -0,0 +1,18 @@
+pub mod newtons_method;
+
+pub trait Solution {
+    fn maximum_groups(grades: Vec<i32>) -> i32;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Solution;
+
+    pub fn run<S: Solution>() {
+        let test_cases = [(&[10, 6, 12, 7, 3, 5] as &[_], 3), (&[8, 8], 1)];
+
+        for (grades, expected) in test_cases {
+            assert_eq!(S::maximum_groups(grades.to_vec()), expected);
+        }
+    }
+}
diff --git a/src/problem_2358_maximum_number_of_groups_entering_a_competition/newtons_method.rs b/src/problem_2358_maximum_number_of_groups_entering_a_competition/newtons_method.rs
new file mode 100644
index 00000000..d70d37cb
--- /dev/null
+++ b/src/problem_2358_maximum_number_of_groups_entering_a_competition/newtons_method.rs
@@ -0,0 +1,37 @@
+pub struct Solution;
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl Solution {
+    pub fn maximum_groups(grades: Vec<i32>) -> i32 {
+        let n = grades.len();
+        let n_times_2 = n * 2;
+        let mut guess = n;
+
+        loop {
+            let new_guess = (guess * guess + n_times_2) / (guess * 2 + 1);
+
+            if new_guess < guess {
+                guess = new_guess;
+            } else {
+                return guess as _;
+            }
+        }
+    }
+}
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl super::Solution for Solution {
+    fn maximum_groups(grades: Vec<i32>) -> i32 {
+        Self::maximum_groups(grades)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_solution() {
+        super::super::tests::run::<super::Solution>();
+    }
+}