From ecb86cb5e5d395708a6aba4f78dd295d83cd4169 Mon Sep 17 00:00:00 2001
From: EFanZh <efanzh@gmail.com>
Date: Sun, 14 Jan 2024 22:05:30 +0800
Subject: [PATCH] Add problem 1751: Maximum Number of Events That Can Be
 Attended II

---
 src/lib.rs                                    |  1 +
 .../dynamic_programming.rs                    | 74 +++++++++++++++++++
 .../mod.rs                                    | 23 ++++++
 3 files changed, 98 insertions(+)
 create mode 100644 src/problem_1751_maximum_number_of_events_that_can_be_attended_ii/dynamic_programming.rs
 create mode 100644 src/problem_1751_maximum_number_of_events_that_can_be_attended_ii/mod.rs

diff --git a/src/lib.rs b/src/lib.rs
index 7ae14ea9..5cc96ca5 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1306,6 +1306,7 @@ pub mod problem_1745_palindrome_partitioning_iv;
 pub mod problem_1748_sum_of_unique_elements;
 pub mod problem_1749_maximum_absolute_sum_of_any_subarray;
 pub mod problem_1750_minimum_length_of_string_after_deleting_similar_ends;
+pub mod problem_1751_maximum_number_of_events_that_can_be_attended_ii;
 pub mod problem_1752_check_if_array_is_sorted_and_rotated;
 pub mod problem_1753_maximum_score_from_removing_stones;
 pub mod problem_1754_largest_merge_of_two_strings;
diff --git a/src/problem_1751_maximum_number_of_events_that_can_be_attended_ii/dynamic_programming.rs b/src/problem_1751_maximum_number_of_events_that_can_be_attended_ii/dynamic_programming.rs
new file mode 100644
index 00000000..200f93db
--- /dev/null
+++ b/src/problem_1751_maximum_number_of_events_that_can_be_attended_ii/dynamic_programming.rs
@@ -0,0 +1,74 @@
+pub struct Solution;
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+use std::cell::Cell;
+use std::convert::TryInto;
+
+impl Solution {
+    pub fn max_value(events: Vec<Vec<i32>>, k: i32) -> i32 {
+        let mut events = events
+            .into_iter()
+            .map(|event| {
+                let [start, end, value]: [_; 3] = event.try_into().ok().unwrap();
+
+                (end as u32, start as u32, value as u32, Cell::new(0_u32))
+            })
+            .collect::<Box<_>>();
+
+        let k = k as u32 as usize;
+
+        events.sort_unstable();
+
+        for (i, event) in events.iter().enumerate() {
+            event.3.set(
+                events[..i]
+                    .partition_point(|prev_event| prev_event.0 < event.1)
+                    .wrapping_sub(1) as _,
+            );
+        }
+
+        let mut cache = vec![0; k * events.len()].into_boxed_slice();
+
+        for (i, event) in events.iter().enumerate() {
+            let (prev_rows, row) = cache[..k * (i + 1)].split_at_mut(k * i);
+
+            for (j, value) in row.iter_mut().enumerate() {
+                let value_if_drop = prev_rows
+                    .get(k.wrapping_mul(i.wrapping_sub(1)).wrapping_add(j))
+                    .copied()
+                    .unwrap_or(0);
+
+                let value_if_choose = if j == 0 {
+                    event.2
+                } else {
+                    prev_rows
+                        .get(k.wrapping_mul(event.3.get() as usize).wrapping_add(j - 1))
+                        .copied()
+                        .unwrap_or(0)
+                        + event.2
+                };
+
+                *value = value_if_drop.max(value_if_choose);
+            }
+        }
+
+        *cache.last().unwrap() as _
+    }
+}
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl super::Solution for Solution {
+    fn max_value(events: Vec<Vec<i32>>, k: i32) -> i32 {
+        Self::max_value(events, k)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_solution() {
+        super::super::tests::run::<super::Solution>();
+    }
+}
diff --git a/src/problem_1751_maximum_number_of_events_that_can_be_attended_ii/mod.rs b/src/problem_1751_maximum_number_of_events_that_can_be_attended_ii/mod.rs
new file mode 100644
index 00000000..db0cdfe6
--- /dev/null
+++ b/src/problem_1751_maximum_number_of_events_that_can_be_attended_ii/mod.rs
@@ -0,0 +1,23 @@
+pub mod dynamic_programming;
+
+pub trait Solution {
+    fn max_value(events: Vec<Vec<i32>>, k: i32) -> i32;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Solution;
+
+    pub fn run<S: Solution>() {
+        let test_cases = [
+            ((&[[1, 2, 4], [3, 4, 3], [2, 3, 1]] as &[_], 2), 7),
+            ((&[[1, 2, 4], [3, 4, 3], [2, 3, 10]], 2), 10),
+            ((&[[1, 1, 1], [2, 2, 2], [3, 3, 3], [4, 4, 4]], 3), 9),
+            ((&[[30, 40, 34], [6, 11, 6], [60, 81, 36]], 1), 36),
+        ];
+
+        for ((events, k), expected) in test_cases {
+            assert_eq!(S::max_value(events.iter().map(Vec::from).collect(), k), expected,);
+        }
+    }
+}