60. Permutation Sequence (java)

Author: bluesword12350

solution/0060.Permutation Sequence/Solution.java

@@ -0,0 +1,20 @@
+class Solution {
+    public String getPermutation(int n, int k) {
+        StringBuilder s = new StringBuilder();
+        int[] fact = new int[n];
+        fact[0] = 1;
+        for (int i = 1; i < n; i++)
+            fact[i] = fact[i - 1] * i;
+        List<Integer> list = new ArrayList<>();
+        for (int i = 1; i <= n; i++)
+            list.add(i);
+        k--;
+        for (int i = n; i >= 1; i--) {
+            int j=k/fact[i-1];
+            k=k%fact[i-1];
+            s.append(list.get(j));
+            list.remove(j);
+        }
+        return s.toString();
+    }
+}