[LeetCode] 31. Next Permutation

这道题卡了好久，终于做出来了，都要绕晕了ㄟ(▔▽▔)ㄏ

	class Solution {
	public void nextPermutation(int[] nums) {
	// Find longest non-increasing suffix
	int i = nums.length - 1;
	while (i > 0 && nums[i] <= nums[i - 1]) {
	i--;
	}
	int pivot = i - 1;
	if (pivot != -1) {
	// Find rightmost successor to pivot in the suffix
	int rightmostSuccessor = nums.length - 1;
	while (nums[rightmostSuccessor] <= nums[pivot]) {
	rightmostSuccessor--;
	}
	// Swap with pivot
	int tmp = nums[pivot];
	nums[pivot] = nums[rightmostSuccessor];
	nums[rightmostSuccessor] = tmp;
	}
	// Reverse the suffix
	int start = pivot + 1;
	int end = nums.length - 1;
	while (start < end) {
	int tmp = nums[start];
	nums[start] = nums[end];
	nums[end] = tmp;
	start++;
	end--;
	}
	}
	}

view raw nextPermutation.java hosted with ❤ by GitHub

比较无聊的一点是，如果没有看到这个算法，是不太可能做出来的 Next lexicographical permutation algorithm