From 35b0ca9eba6ac52f6e2164d1c0a3a69fd199f419 Mon Sep 17 00:00:00 2001
From: EFanZh <efanzh@gmail.com>
Date: Wed, 22 Nov 2023 20:21:30 +0800
Subject: [PATCH] Add problem 1963: Minimum Number of Swaps to Make the String
 Balanced

---
 src/lib.rs                                    |  1 +
 .../iterative.rs                              | 37 +++++++++++++++++++
 .../mod.rs                                    | 18 +++++++++
 3 files changed, 56 insertions(+)
 create mode 100644 src/problem_1963_minimum_number_of_swaps_to_make_the_string_balanced/iterative.rs
 create mode 100644 src/problem_1963_minimum_number_of_swaps_to_make_the_string_balanced/mod.rs

diff --git a/src/lib.rs b/src/lib.rs
index bf769b5b..f127b44b 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -1362,6 +1362,7 @@ pub mod problem_1952_three_divisors;
 pub mod problem_1957_delete_characters_to_make_fancy_string;
 pub mod problem_1961_check_if_string_is_a_prefix_of_array;
 pub mod problem_1962_remove_stones_to_minimize_the_total;
+pub mod problem_1963_minimum_number_of_swaps_to_make_the_string_balanced;
 pub mod problem_1967_number_of_strings_that_appear_as_substrings_in_word;
 pub mod problem_1968_array_with_elements_not_equal_to_average_of_neighbors;
 
diff --git a/src/problem_1963_minimum_number_of_swaps_to_make_the_string_balanced/iterative.rs b/src/problem_1963_minimum_number_of_swaps_to_make_the_string_balanced/iterative.rs
new file mode 100644
index 00000000..c654f820
--- /dev/null
+++ b/src/problem_1963_minimum_number_of_swaps_to_make_the_string_balanced/iterative.rs
@@ -0,0 +1,37 @@
+pub struct Solution;
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl Solution {
+    pub fn min_swaps(s: String) -> i32 {
+        let mut stack = 0_u32;
+
+        for c in s.into_bytes() {
+            stack = stack.wrapping_add(if c == b'[' {
+                1
+            } else if stack == 0 {
+                0
+            } else {
+                u32::MAX
+            });
+        }
+
+        ((stack + 1) / 2) as _
+    }
+}
+
+// ------------------------------------------------------ snip ------------------------------------------------------ //
+
+impl super::Solution for Solution {
+    fn min_swaps(s: String) -> i32 {
+        Self::min_swaps(s)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    #[test]
+    fn test_solution() {
+        super::super::tests::run::<super::Solution>();
+    }
+}
diff --git a/src/problem_1963_minimum_number_of_swaps_to_make_the_string_balanced/mod.rs b/src/problem_1963_minimum_number_of_swaps_to_make_the_string_balanced/mod.rs
new file mode 100644
index 00000000..e7b12083
--- /dev/null
+++ b/src/problem_1963_minimum_number_of_swaps_to_make_the_string_balanced/mod.rs
@@ -0,0 +1,18 @@
+pub mod iterative;
+
+pub trait Solution {
+    fn min_swaps(s: String) -> i32;
+}
+
+#[cfg(test)]
+mod tests {
+    use super::Solution;
+
+    pub fn run<S: Solution>() {
+        let test_cases = [("][][", 1), ("]]][[[", 2), ("[]", 0)];
+
+        for (s, expected) in test_cases {
+            assert_eq!(S::min_swaps(s.to_string()), expected);
+        }
+    }
+}