20250205 finished.

src/problem/mod.rs

@@ -470,3 +470,5 @@ mod p598_range_addition_ii;
 mod p680_valid_palindrome_ii;
 
 mod p922_sort_array_by_parity_ii;
+
+mod p90_subsets_ii;

src/problem/p90_subsets_ii.rs

@@ -0,0 +1,68 @@
+/**
+ * [90] Subsets II
+ */
+pub struct Solution {}
+
+// submission codes start here
+
+impl Solution {
+    pub fn subsets_with_dup(mut nums: Vec<i32>) -> Vec<Vec<i32>> {
+        let mut result = Vec::with_capacity(2usize.pow(nums.len() as u32));
+        let mut path = Vec::with_capacity(nums.len());
+
+        nums.sort_unstable();
+        Self::search(&nums, &mut path, 0, false, &mut result);
+
+        result
+    }
+
+    pub fn search(
+        nums: &Vec<i32>,
+        path: &mut Vec<i32>,
+        pos: usize,
+        choose: bool,
+        result: &mut Vec<Vec<i32>>,
+    ) {
+        if pos == nums.len() {
+            result.push(path.clone());
+            return;
+        }
+
+        // 不选择pos
+        Self::search(nums, path, pos + 1, false, result);
+
+        // 选择pos
+        // 如果nums[pos - 1] == nums[pos - 1] 且没有选择前一个数
+        // 说明选择重复了
+        if !choose && pos > 0 && nums[pos - 1] == nums[pos] {
+            return;
+        } else {
+            path.push(nums[pos]);
+            Self::search(nums, path, pos + 1, true, result);
+            path.pop();
+        }
+    }
+}
+
+// submission codes end
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+
+    #[test]
+    fn test_90() {
+        assert_eq!(
+            vec![
+                vec![],
+                vec![2],
+                vec![2, 2],
+                vec![1],
+                vec![1, 2],
+                vec![1, 2, 2],
+            ],
+            Solution::subsets_with_dup(vec![1, 2, 2])
+        );
+        assert_eq!(vec![vec![], vec![0]], Solution::subsets_with_dup(vec![0]));
+    }
+}