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T39:和為S的連續正數序列(Java)

題目:輸出所有和為S的連續正數序列。序列內按照從小至大的順序,序列間按照開始數字從小到大的順序

比如 輸入15

輸出為

public class FindContinuousSequence1 {
	 public static ArrayList<ArrayList<Integer> > FindContinuousSequence(int sum) {
		 ArrayList<ArrayList<Integer>> listAll=new  ArrayList<ArrayList<Integer> >();
		if(sum<3){
			return listAll;
		}
		 int small=1;
		 int big=2;
		 int mid=(1+sum)/2;
		 int curSum=3;
		 while(small<mid){
			 while(curSum>sum&&small<mid){
				 curSum-=small;
				 small++;
			 }
			 if(curSum==sum){
				 ArrayList<Integer> list=new  ArrayList<Integer>();
				 add(list,small,big);
				 listAll.add(list);
			 }
			 big++;
			 curSum+=big;
		 }
		 
		 return listAll;
	       
	    }

	private static void add(ArrayList<Integer> list, int small, int big) {
		for(int i=small;i<=big;i++){
			list.add(i);
		}
	}
	
	public static void main(String[] args) {
		ArrayList<ArrayList<Integer>> listAll=FindContinuousSequence(15);
		
		for(ArrayList list:listAll){
			System.out.println(list);
		}
	}
}