From d9b5ef618fb7ade4173d8a886f4da795bfad9a8c Mon Sep 17 00:00:00 2001
From: jackfiled <xcrenchangjun@outlook.com>
Date: Sun, 30 Mar 2025 14:21:30 +0800
Subject: [PATCH] 20250330 finished.

---
 src/problem/mod.rs                            |  2 +
 .../p2109_adding_spaces_to_a_string.rs        | 50 +++++++++++++++++++
 2 files changed, 52 insertions(+)
 create mode 100644 src/problem/p2109_adding_spaces_to_a_string.rs

diff --git a/src/problem/mod.rs b/src/problem/mod.rs
index defa2b1..f4c7c94 100644
--- a/src/problem/mod.rs
+++ b/src/problem/mod.rs
@@ -568,3 +568,5 @@ mod p2712_minimum_cost_to_make_all_characters_equal;
 mod p2716_minimize_string_length;
 
 mod p2360_longest_cycle_in_a_graph;
+
+mod p2109_adding_spaces_to_a_string;
diff --git a/src/problem/p2109_adding_spaces_to_a_string.rs b/src/problem/p2109_adding_spaces_to_a_string.rs
new file mode 100644
index 0000000..1a412e1
--- /dev/null
+++ b/src/problem/p2109_adding_spaces_to_a_string.rs
@@ -0,0 +1,50 @@
+/**
+ * [2109] Adding Spaces to a String
+ */
+pub struct Solution {}
+
+// submission codes start here
+
+impl Solution {
+    pub fn add_spaces(s: String, spaces: Vec<i32>) -> String {
+        let s: Vec<char> = s.chars().collect();
+        let mut result = Vec::with_capacity(s.len() + spaces.len());
+        let mut iter = spaces.into_iter().peekable();
+
+        for (i, v) in s.into_iter().enumerate() {
+            if let Some(&pos) = iter.peek() {
+                if i == pos as usize {
+                    iter.next();
+                    result.push(' ');
+                }
+            }
+
+            result.push(v);
+        }
+
+        result.into_iter().collect()
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_2109() {
+        assert_eq!(
+            "Leetcode Helps Me Learn",
+            Solution::add_spaces("LeetcodeHelpsMeLearn".to_owned(), vec![8, 13, 15])
+        );
+        assert_eq!(
+            "i code in py thon",
+            Solution::add_spaces("icodeinpython".to_owned(), vec![1, 5, 7, 9])
+        );
+        assert_eq!(
+            " s p a c i n g",
+            Solution::add_spaces("spacing".to_owned(), vec![0, 1, 2, 3, 4, 5, 6])
+        );
+    }
+}