From 330a5720493fab5975f3413747f627e84eaf14fe Mon Sep 17 00:00:00 2001
From: EFanZh <efanzh@gmail.com>
Date: Thu, 9 May 2024 13:34:33 +0800
Subject: [PATCH] Add problem 1910: Remove All Occurrences of a Substring

---
 src/lib.rs                                    |  1 +
 .../kmp.rs                                    | 83 +++++++++++++++++++
 .../mod.rs                                    | 22 +++++
 3 files changed, 106 insertions(+)
 create mode 100644 src/problem_1910_remove_all_occurrences_of_a_substring/kmp.rs
 create mode 100644 src/problem_1910_remove_all_occurrences_of_a_substring/mod.rs

diff --git a/src/lib.rs b/src/lib.rs
index 5f3384ed..878707f1 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1414,6 +1414,7 @@ pub mod problem_1903_largest_odd_number_in_string;
 pub mod problem_1904_the_number_of_full_rounds_you_have_played;
 pub mod problem_1906_minimum_absolute_difference_queries;
 pub mod problem_1909_remove_one_element_to_make_the_array_strictly_increasing;
+pub mod problem_1910_remove_all_occurrences_of_a_substring;
 pub mod problem_1911_maximum_alternating_subsequence_sum;
 pub mod problem_1913_maximum_product_difference_between_two_pairs;
 pub mod problem_1915_number_of_wonderful_substrings;
diff --git a/src/problem_1910_remove_all_occurrences_of_a_substring/kmp.rs b/src/problem_1910_remove_all_occurrences_of_a_substring/kmp.rs
new file mode 100644
index 00000000..37bb35b7
--- /dev/null
+++ b/src/problem_1910_remove_all_occurrences_of_a_substring/kmp.rs
@@ -0,0 +1,83 @@
+pub struct Solution;
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl Solution {
+    fn compute_kmp_table(s: &[u8]) -> Box<[u16]> {
+        let mut result = vec![0; s.len()].into_boxed_slice();
+        let mut matched = 0;
+        let mut i = 1;
+
+        while let Some(&c) = s.get(i) {
+            loop {
+                if c == s[matched] {
+                    matched += 1;
+                    result[i] = matched as _;
+
+                    break;
+                } else if let Some(&next_matched) = result.get(matched.wrapping_sub(1)) {
+                    matched = usize::from(next_matched);
+                } else {
+                    break;
+                }
+            }
+
+            i += 1;
+        }
+
+        result
+    }
+
+    pub fn remove_occurrences(s: String, part: String) -> String {
+        let mut s = s.into_bytes();
+        let part = part.as_bytes();
+        let kmp_table = Self::compute_kmp_table(part);
+        let mut matched = 0;
+        let mut match_history = Vec::<u16>::with_capacity(s.len());
+        let mut i = 0;
+
+        while let Some(&c) = s.get(i) {
+            loop {
+                if c == part[matched] {
+                    matched += 1;
+
+                    break;
+                } else if let Some(&next_matched) = kmp_table.get(matched.wrapping_sub(1)) {
+                    matched = usize::from(next_matched);
+                } else {
+                    break;
+                }
+            }
+
+            if matched == part.len() {
+                match_history.truncate(match_history.len() - (part.len() - 1));
+                matched = usize::from(match_history.last().copied().unwrap_or_default());
+            } else {
+                s[match_history.len()] = c;
+                match_history.push(matched as _);
+            }
+
+            i += 1;
+        }
+
+        s.truncate(match_history.len());
+
+        String::from_utf8(s).ok().unwrap()
+    }
+}
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl super::Solution for Solution {
+    fn remove_occurrences(s: String, part: String) -> String {
+        Self::remove_occurrences(s, part)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_solution() {
+        super::super::tests::run::<super::Solution>();
+    }
+}
diff --git a/src/problem_1910_remove_all_occurrences_of_a_substring/mod.rs b/src/problem_1910_remove_all_occurrences_of_a_substring/mod.rs
new file mode 100644
index 00000000..993cde93
--- /dev/null
+++ b/src/problem_1910_remove_all_occurrences_of_a_substring/mod.rs
@@ -0,0 +1,22 @@
+pub mod kmp;
+
+pub trait Solution {
+    fn remove_occurrences(s: String, part: String) -> String;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Solution;
+
+    pub fn run<S: Solution>() {
+        let test_cases = [
+            (("daabcbaabcbc", "abc"), "dab"),
+            (("axxxxyyyyb", "xy"), "ab"),
+            (("gjzgbpggjzgbpgsvpwdk", "gjzgbpg"), "svpwdk"),
+        ];
+
+        for ((s, part), expected) in test_cases {
+            assert_eq!(S::remove_occurrences(s.to_string(), part.to_string()), expected);
+        }
+    }
+}