Palindrome Permutation II Palindrome Permutation Minimum Adjacent Swaps to Reach the Kth Smallest Number 参考资料: https://leetcode.com/problems/next-permutation/ https://leetcode.com/problems/next-permutation/discuss/13921/1-4-11-lines-C%2B%2B https://leetcode.com/problems/next-permutation/discuss/13867/C%2B%2B-from-Wikipedia ...