递归求字符串的所有组合

Question

想问下这个求所有组合的递归具体该怎么实现呢，想了好久了，问了好多次都没人回答

Answer 1

第一步先求字符的集合，删除重复字母，再进行排序，这个容易。
第二步不怎么好解，这有详细说明和 c code，有method 1, method 2...

Print all possible combinations of r elements in a given array of size n - GeeksforGeeks A Computer Science portal for geeks. It contains well written, well thought and well explained computer science and programming articles, quizzes and practice/competitive programming/company interview Questions. https://www.geeksforgeeks.org/print-all-possible-combinations-of-r-elements-in-a-given-array-of-size-n/

code 里稍微修改一下，比如 int array 改成 char array
for (int i=1; i <= 3; i++)
printCombination(arr, n, i);
然后就可以打印出结果. a, b, c, ab, ....

然后这也有code:

all possible combinations in a string in C - Stack Overflow I am trying to print all possible combinations of the string 'abc' using C. Can someone help point out where in this code I am going wrong ? I am using the algorithm mentioned here: http://hackercs... https://stackoverflow.com/questions/7441571/all-possible-combinations-in-a-string-in-c