在我的相关问题评论之后，这是一个Java实现，可以使用Counting QuickPerm
Algorithm来完成您想要的事情：
public static void combString(String s) { // Print initial string, as only the alterations will be printed later System.out.println(s); char[] a = s.toCharArray(); int n = a.length; int[] p = new int[n]; // Weight index control array initially all zeros. Of course, same size of the char array. int i = 1; //Upper bound index. i.e: if string is "abc" then index i could be at "c" while (i < n) { if (p[i] < i) { //if the weight index is bigger or the same it means that we have already switched between these i,j (one iteration before). int j = ((i % 2) == 0) ? 0 : p[i];//Lower bound index. i.e: if string is "abc" then j index will always be 0. swap(a, i, j); // Print current System.out.println(join(a)); p[i]++; //Adding 1 to the specific weight that relates to the char array. i = 1; //if i was 2 (for example), after the swap we now need to swap for i=1 } else { p[i] = 0;//Weight index will be zero because one iteration before, it was 1 (for example) to indicate that char array a[i] swapped. i++;//i index will have the option to go forward in the char array for "longer swaps" } }}private static String join(char[] a) { StringBuilder builder = new StringBuilder(); builder.append(a); return builder.toString();}private static void swap(char[] a, int i, int j) { char temp = a[i]; a[i] = a[j]; a[j] = temp;}
