forked from leetcoders/LeetCode
-
Notifications
You must be signed in to change notification settings - Fork 0
/
Copy pathPermutationSequence.h
46 lines (44 loc) · 1.01 KB
/
PermutationSequence.h
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
/*
Author: Annie Kim, [email protected]
Date: May 8, 2013
Update: Aug 12, 2013
Problem: Permutation Sequence
Difficulty: Medium
Source: http://leetcode.com/onlinejudge#question_60
Notes:
The set [1,2,3,...,n] contains a total of n! unique permutations.
By listing and labeling all of the permutations in order,
We get the following sequence (ie, for n = 3):
"123"
"132"
"213"
"231"
"312"
"321"
Given n and k, return the kth permutation sequence.
Note: Given n will be between 1 and 9 inclusive.
Solution: ...
*/
class Solution {
public:
string getPermutation(int n, int k) {
string num, res;
int total = 1;
for (int i = 1; i <= n; ++i)
{
num.push_back(i + '0');
total *= i;
}
k--;
while (n)
{
total /= n;
int i = k / total;
k %= total;
res.push_back(num[i]);
num.erase(i, 1);
n--;
}
return res;
}
};