/
Permutations_of_a_given_string.java
62 lines (54 loc) · 1.27 KB
/
Permutations_of_a_given_string.java
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
// { Driver Code Starts
import java.util.*;
import java.lang.*;
import java.io.*;
class GFG {
public static void main(String[] args) throws IOException {
BufferedReader br = new BufferedReader(new InputStreamReader(System.in));
int t = Integer.parseInt(br.readLine().trim());
while (t-- > 0) {
String S = br.readLine().trim();
Solution obj = new Solution();
List<String> ans = obj.find_permutation(S);
for (int i = 0; i < ans.size(); i++) {
System.out.print(ans.get(i) + " ");
}
System.out.println();
}
}
}
class Solution {
List<String> ans = new ArrayList<>();
public List<String> find_permutation(String S) {
int n = S.length();
if (n <= 1) {
ans.add(S);
return ans;
}
findPermutation(S, 0, n - 1);
Collections.sort(ans);
return ans;
}
void findPermutation(String s, int start, int end) {
if (start == end) {
ans.add(s);
} else {
for (int i = start; i <= end; i++) {
String str = reverse(s, start, i);
findPermutation(str, start + 1, end);
reverse(str, start, i);
}
}
}
String reverse(String str, int left, int right) {
char[] arr = str.toCharArray();
while (left <= right) {
char temp = arr[left];
arr[left] = arr[right];
arr[right] = temp;
left++;
right--;
}
return new String(arr);
}
}