add 60

Author: luliyucoordinate

README.md

@@ -59,6 +59,7 @@ LeetCode
 |0056|[Merge Intervals](https://leetcode.com/problems/merge-intervals/) | c | [c++](./src/0056-Merge-Intervals/0055.cpp) |[python](./src/0056-Merge-Intervals/0055.py)|||Medium|
 |0058|[Length of Last Word](https://leetcode.com/problems/length-of-last-word/) | c | [c++](./src/0058-Length-of-Last-Word/0058.cpp) |[python](./src/0058-Length-of-Last-Word/0058.py)|||Easy|
 |0059|[Spiral Matrix II](https://leetcode.com/problem/spiral-matrix-ii/) | c | [c++](./src/0059-Spiral-Matrix-II/0059.cpp) |[python](./src/0059-Spiral-Matrix-II/0059.py)|||Hard|
+|0060|[Permutation Sequence](https://leetcode.com/problems/permutation-sequence/) | c | [c++](./src/0060-Permutation-Sequence/0060.cpp) |[python](./src/0060-Permutation-Sequence/0060.py)|||Medium|
 |0061|[Rotate List](https://leetcode.com/problems/rotate-list/) | c | [c++](./src/0061-Rotate-List/0061.cpp) |[python](./src/0061-Rotate-List/0061.py)|||Medium|
 |0062|[Unique Paths](https://leetcode.com/problems/unique-paths/) | c | [c++](./src/0062-Unique-Paths/0062.cpp) |[python](./src/0062-Unique-Paths/0062.py)|||Medium|
 |0063|[Unique Paths II](https://leetcode.com/problems/unique-paths-ii/) | c | [c++](./src/0063-Unique-Paths-II/0063.cpp) |[python](./src/0063-Unique-Paths-II/0063.py)|||Medium|

src/0060-Permutation-Sequence/0060.cpp

@@ -0,0 +1,24 @@
+static int x = []() {std::ios::sync_with_stdio(false); cin.tie(0); return 0; }();
+class Solution 
+{
+public:
+    string getPermutation(int n, int k) 
+    {
+        string res;
+        int fac = 1;
+        for (int i = 1; i <= n; ++i) 
+        {
+            res.push_back('0' + i);
+            fac *= i;
+        }
+        --k;
+        for (auto first = res.begin(); n > 0; --n, ++first) 
+        {
+            fac /= n; 
+            auto index = first + k / fac;
+            rotate(first, index, index+1);
+            k %= fac;
+        }
+        return res;
+    }
+};

src/0060-Permutation-Sequence/0060.py

@@ -0,0 +1,28 @@
+class Solution:
+    def getPermutation(self, n, k):
+        """
+        :type n: int
+        :type k: int
+        :rtype: str
+        """
+        factorials = [1]*(n+1)
+        for i in range(1, n+1):
+            factorials[i] = factorials[i-1]*i
+            
+        n_list = [i for i in range(1, n+1)]
+        return self.helper(n, k-1, n_list, factorials)
+    
+    def helper(self, n, k, n_list, factorials):
+        if n == 1:
+            return str(n_list[0])
+        
+        m = k // factorials[n-1]
+        k %= factorials[n-1]     
+        res = str(n_list[m])
+        n_list.remove(n_list[m])
+        res += self.helper(n-1, k, n_list, factorials)
+        return res
+
+if __name__ == "__main__":
+    n, k = 4, 14
+    print(Solution().getPermutation(n, k))