diff --git a/leetCode/math/combination-sum.rs b/leetCode/math/combination-sum.rs
new file mode 100644
index 0000000..bca080b
--- /dev/null
+++ b/leetCode/math/combination-sum.rs
@@ -0,0 +1,41 @@
+// https://leetcode.com/problems/combination-sum/
+use std::collections::HashSet;
+
+impl Solution {
+    pub fn combination_sum(candidates: Vec<i32>, target: i32) -> Vec<Vec<i32>> {
+        let mut resp: HashSet<Vec<i32>> = HashSet::new();
+
+        for candidate in &candidates {
+            if *candidate == target{
+                resp.insert(vec![*candidate]);
+                break;
+            }
+        }
+
+        let mut pilha = vec![(Vec::new(), 0)];
+        while !pilha.is_empty() {
+            if resp.len() == 150 {
+                break;
+            }
+            
+            let (it, sum) = pilha.pop().unwrap();
+
+            for candidate in &candidates {
+                if sum + *candidate < target {
+                    let mut new_it = it.clone();
+                    new_it.push(*candidate);
+
+                    pilha.push((new_it, sum + *candidate));
+                } else if sum + *candidate == target {
+                    let mut new_it = it.clone();
+                    new_it.push(*candidate);
+                    new_it.sort();
+
+                    resp.insert(new_it);
+                }
+            }
+        }
+
+        resp.into_iter().collect()
+    }
+}