Untitled

class Solution {
public:
    void backtrack(vector<int>& nums, int target, int start, vector<int>& curr, vector<vector<int>>& result) {
        if (target == 0) {
            result.push_back(curr);
            return;
        }

        for (int i = start; i < nums.size(); ++i) {
            if (nums[i] > target) break; 

            curr.push_back(nums[i]);
            backtrack(nums, target - nums[i], i, curr, result); 
            curr.pop_back();
        }
    }

    vector<vector<int>> combinationSum(vector<int>& nums, int target) {
        sort(nums.begin(), nums.end()); // Enables pruning
        vector<vector<int>> result;
        vector<int> curr;
        backtrack(nums, target, 0, curr, result);
        return result;
    }
};