Create 0039-combination-sum.rs

Author: nirajvenkat

rust/0039-combination-sum.rs

@@ -0,0 +1,24 @@
+impl Solution {
+    fn dfs(candidates: &[i32], target: i32, result: &mut Vec<Vec<i32>>, curr: &mut Vec<i32>) {
+        let sum: i32 = curr.iter().sum();
+        if sum == target {
+            result.push(curr.to_owned());
+            return;
+        } else if sum > target {
+            return;
+        }
+
+        for (i, &c) in candidates.iter().enumerate() {
+            curr.push(c);
+            Self::dfs(&candidates[i..], target, result, curr);
+            curr.pop();
+        }
+    }
+
+    pub fn combination_sum(candidates: Vec<i32>, target: i32) -> Vec<Vec<i32>> {
+        let (mut result, mut curr) = (vec![], vec![]);
+        Self::dfs(&candidates, target, &mut result, &mut curr);
+        
+        result
+    }
+}