package algorithms; /** * @Auther: Jesper * @Date: 2019/2/12 17:23 * @Description: 全排列 */ public class Permutation { int count = 0; public void permutation(char[] cs, int index) { if (index > cs.length) { return; } if (index == cs.length) { System.out.println(new String(cs)); count++; } for (int i = index; i < cs.length; i++) { swap(cs, index, i); permutation(cs, index + 1); // 再次交换，保持原状 swap(cs, index, i); } } private void swap(char[] cs, int index, int target) { char tmp = cs[index]; cs[index] = cs[target]; cs[target] = tmp; } public static void main(String[] args) { char[] cs = new char[]{'a', 'b', 'c', 'd'}; Permutation per = new Permutation(); per.permutation(cs, 0); System.out.println("方法总数:" + per.count); } }