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| class Solution {
List<List<Integer>> result = new ArrayList<>();
List<Integer> ans = new ArrayList<>();
public List<List<Integer>> combinationSum3(int k, int n) {
int[] arr = new int[]{1,2,3,4,5,6,7,8,9};
dfs(arr, 0, k, n);
return result;
}
public void dfs(int[] arr, int begin, int k, int n){
if (n == 0 && k == 0){
result.add(new ArrayList<Integer>(ans));
return;
}
if (k <= 0){
return;
}
for (int i = begin; i < arr.length; i++) {
ans.add(arr[i]);
dfs(arr, i + 1, k - 1, n - arr[i]);
ans.remove(ans.size() - 1);
}
}
}
|
