Create 0046-permutations.rs

Author: nirajvenkat

rust/0046-permutations.rs

@@ -0,0 +1,21 @@
+impl Solution {
+    fn backtrack(first: usize, result: &mut Vec<Vec<i32>>, nums: &mut Vec<i32>) {
+        if first == nums.len() {
+            result.push(nums.to_owned());
+            return;
+        }
+
+        for i in first..nums.len() {
+            nums.swap(first, i);
+            Solution::backtrack(first + 1, result, nums);
+            nums.swap(first, i);
+        }
+    }
+
+    pub fn permute(nums: Vec<i32>) -> Vec<Vec<i32>> {
+        let (mut result, mut nums) = (vec![], nums);
+        Self::backtrack(0, &mut result, &mut nums);
+
+        result
+    }
+}