From e3590fe7418b05cb63dd26700fae751aba77a0b8 Mon Sep 17 00:00:00 2001
From: jackfiled <xcrenchangjun@outlook.com>
Date: Fri, 5 Jul 2024 10:10:47 +0800
Subject: [PATCH] 20240705 Finished

---
 src/problem/mod.rs              |  3 +-
 src/problem/p46_permutations.rs | 49 +++++++++++++++++++++++++++++++++
 2 files changed, 51 insertions(+), 1 deletion(-)
 create mode 100644 src/problem/p46_permutations.rs

diff --git a/src/problem/mod.rs b/src/problem/mod.rs
index b7bcd4e..b35cd27 100644
--- a/src/problem/mod.rs
+++ b/src/problem/mod.rs
@@ -166,4 +166,5 @@ mod p208_implement_trie_prefix_tree;
 mod p211_design_add_and_search_words_data_structure;
 mod p212_word_search_ii;
 mod p17_letter_combinations_of_a_phone_number;
-mod p77_combinations;
\ No newline at end of file
+mod p77_combinations;
+mod p46_permutations;
\ No newline at end of file
diff --git a/src/problem/p46_permutations.rs b/src/problem/p46_permutations.rs
new file mode 100644
index 0000000..98716fd
--- /dev/null
+++ b/src/problem/p46_permutations.rs
@@ -0,0 +1,49 @@
+/**
+ * [46] Permutations
+ */
+pub struct Solution {}
+
+
+// submission codes start here
+
+impl Solution {
+    pub fn permute(nums: Vec<i32>) -> Vec<Vec<i32>> {
+        let mut result = vec![];
+        let mut output = nums.clone();
+
+        Self::search(output.len(), &mut output, &mut result, 0);
+
+        result
+    }
+
+    fn search(length: usize, output: &mut Vec<i32>, result: &mut Vec<Vec<i32>>, pos: usize) {
+        if length == pos {
+            result.push(output.clone());
+            return;
+        }
+        
+        for i in pos..length {
+            Self::swap(output, i, pos);
+            Self::search(length, output, result, pos + 1);
+            Self::swap(output, i, pos);
+        }
+        
+    }
+    
+    fn swap(output: &mut Vec<i32>, a: usize, b: usize) {
+        let temp = output[a];
+        output[a] = output[b];
+        output[b] = temp;
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_46() {
+    }
+}