Enter two integers, N and m, from the numbers 1, 2, 3 ,...... Random Number in N to make it equal to m

Question: programming, input two integers n and m, from the series 1, 2, 3 ,...... N is random, so that the sum is equal to M. All possible combinations are required.

Analysis: the idea of sub-governance. You can split the problem (m, n) into (m-N, N-1) and (m, n-1 ).

Note: When the value of 1 and N is greater than m, you can start searching from n = m.

2. End condition: n <1 | M <1

3. Print the output result. Note that printing the output result does not mean that the function call is complete. Taking n = 7 and M = 10 as an example, 7, 3, 7, 2, and 1 are all results, cannot be terminated at 7 or 3. The Print Output condition is n = m.

The program code is as follows:

Java

public class FindSum {    // used as a stack to save the result    private static LinkedList<Integer> list = new LinkedList<Integer>();    public static void findSum(int sum, int n) {        if (n < 1 || sum < 1)            return;        if (sum < n)            n = sum;        if (sum == n) {            for (int i = 0; i < list.size(); i++)                System.out.print(list.get(i) + " ");            System.out.print(sum);            System.out.println();        }        list.addLast(n);        findSum(sum - n, n - 1);        list.removeLast();        findSum(sum, n - 1);    }    public static void main(String[] args) {        int sum = 10;        int n = 8;        findSum(sum, n);    }}