20250206 finished.

src/problem/mod.rs

@@ -472,3 +472,5 @@ mod p680_valid_palindrome_ii;
 mod p922_sort_array_by_parity_ii;
 
 mod p90_subsets_ii;
+
+mod p47_permutations_ii;

src/problem/p47_permutations_ii.rs

@@ -0,0 +1,62 @@
+/**
+ * [47] Permutations II
+ */
+pub struct Solution {}
+
+// submission codes start here
+
+impl Solution {
+    pub fn permute_unique(mut nums: Vec<i32>) -> Vec<Vec<i32>> {
+        nums.sort_unstable();
+
+        let mut result = vec![];
+        let mut visited = vec![false; nums.len()];
+        let mut path = Vec::with_capacity(nums.len());
+
+        Self::search(&nums, 0, &mut path, &mut visited, &mut result);
+
+        result
+    }
+
+    fn search(
+        nums: &Vec<i32>,
+        pos: usize,
+        path: &mut Vec<i32>,
+        visited: &mut Vec<bool>,
+        result: &mut Vec<Vec<i32>>,
+    ) {
+        if pos == nums.len() {
+            result.push(path.clone());
+            return;
+        }
+
+        for i in 0..nums.len() {
+            if visited[i] || (i > 0 && nums[i - 1] == nums[i] && !visited[i - 1]) {
+                continue;
+            }
+
+            visited[i] = true;
+
+            path.push(nums[i]);
+            Self::search(nums, pos + 1, path, visited, result);
+            path.pop();
+
+            visited[i] = false;
+        }
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_47() {
+        assert_eq!(
+            vec![vec![1, 1, 2], vec![1, 2, 1], vec![2, 1, 1]],
+            Solution::permute_unique(vec![1, 1, 2])
+        );
+    }
+}