-
Notifications
You must be signed in to change notification settings - Fork 0
Expand file tree
/
Copy pathPermutations.java
More file actions
79 lines (70 loc) · 2.44 KB
/
Permutations.java
File metadata and controls
79 lines (70 loc) · 2.44 KB
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
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
package Recursion;
import java.util.ArrayList;
import java.util.List;
public class Permutations {
private static void permutation(String str,String ans) {
if(str.length() == 0) {
System.out.println(ans);
return;
}
char ch = str.charAt(0);
for(int i = 0;i<=ans.length();i++) {
String f = ans.substring(0, i);
String e = ans.substring(i,ans.length());
permutation(str.substring(1), f+ch+e);
}
}
private static ArrayList<String> permutationArrayList(String str,String ans) {
if(str.length() == 0) {
ArrayList<String> list = new ArrayList<>();
list.add(ans);
return list;
}
char ch = str.charAt(0);
ArrayList<String> arr = new ArrayList<>();
for(int i = 0;i<=ans.length();i++) {
String f = ans.substring(0, i);
String e = ans.substring(i,ans.length());
arr.addAll(permutationArrayList(str.substring(1), f+ch+e));
}
return arr;
}
private static int permutationCount(String str,String ans) {
if(str.length() == 0) {
// System.out.println(ans);
return 1;
}
int count = 0;
char ch = str.charAt(0);
for(int i = 0;i<=ans.length();i++) {
String f = ans.substring(0, i);
String e = ans.substring(i,ans.length());
count+=permutationCount(str.substring(1), f+ch+e);
}
return count;
}
// Array Permutation
static void permutationArray(int[] nums,List<List<Integer>> list,List<Integer> ans,int index) {
if(index == nums.length){
list.add(ans);
return;
}
for(int i = 0;i<=ans.size();i++){
List<Integer> temp = new ArrayList<>(ans) ;
temp.add(i,nums[index]);
permutationArray(nums,list,temp,index+1);
}
}
public static List<List<Integer>> Arraypermute(int[] nums) {
List<List<Integer>> list = new ArrayList<>();
permutationArray(nums,list,new ArrayList<Integer>(),0);
return list;
}
public static void main(String[] args) {
String str = "abc";
permutation(str,"");
System.out.println(permutationArrayList(str,""));
System.out.println(permutationCount("abcd",""));
System.out.println(Arraypermute(new int[] {1,2,3}));
}
}