给一个参数n，求这个数的所有整数求和排列，不允许有重复
给一个参数n，求这个数的所有整数求和排列，不允许有重复
简单解答，算法还有优化空间
public static void main(String[] args) {int n = 10;int[] pre = new int [(int)Math.sqrt(2 * n)];p1(n, 1, pre, 0);}public static void p1 (int n, int start, int[] pre, int index) {int current = 0;for (int j = 0; j < index; j ++) {current += pre[j];}int r = n - current;int max = r % 2 == 0 ? r / 2 - 1 : r / 2;if (start > max) return;for (int i = start; i < max; i ++) {for (int j = 0; j < index; j ++) {System.out.print(pre[j] + " ");}System.out.println(i + " " + (r - i));pre[index] = i;p1(n, i + 1, pre, index + 1);}for (int j = 0; j < index; j ++) {System.out.print(pre[j] + " ");}System.out.println(max + " " + (r - max));}