Given a set of candidate numbers (C) and a target number (T), find all unique combinations in C where the candidate numbers sums to T.
The same repeated number may be chosen from C unlimited number of times.
Note:
All numbers (including target) will be positive integers.
Elements in a combination (a1, a2, … , ak) must be in non-descending order. (ie, a1 ≤ a2 ≤ … ≤ ak).
The solution set must not contain duplicate combinations.
public static List<List<Integer>> combinationSum(int[] candidates, int target) {
bubbleSort(candidates);
List<List<Integer>> arrayLists = new ArrayList<List<Integer>>();
if (candidates==null||candidates.length==0||target<0) {
return arrayLists;
}
List<Integer> arrayList = new ArrayList<Integer>();
getRes(arrayLists, arrayList, candidates, target, 0);
return arrayLists;
}
public static void bubbleSort(int[] arr) {
for (int i = 0; i < arr.length; i++) {
for (int j = 0; j < arr.length-1-i; j++) {
if (arr[j]>arr[j+1]) {
int temp = arr[j];
arr[j] = arr[j+1];
arr[j+1] = temp;
}
}
}
}
private static void getRes(List<List<Integer>> arrayLists,List<Integer> arrayList,int[] arr,int target,int index) {
if (target > 0) {
for (int i = index; i < arr.length ; i++) {
arrayList.add(arr[i]);
getRes(arrayLists, arrayList, arr, target - arr[i], i);
arrayList.remove(arrayList.size() - 1);
}
} else if (target == 0) {
arrayLists.add(new ArrayList<Integer>(arrayList));
}
}