【leetcode】Next Permutation

标签：leetcode   面试题   算法   algorithm   numbers   

问题：

Implement next permutation, which rearranges numbers into the lexicographically next greater permutation of numbers.

If such arrangement is not possible, it must rearrange it as the lowest possible order (ie, sorted in ascending order).

The replacement must be in-place, do not allocate extra memory.

Here are some examples. Inputs are in the left-hand column and its corresponding outputs are in the right-hand column.

void nextPermutation(vector<int> &num) 
{
	if(num.size() <= 1)
		return;
	int i = num.size() - 1;
	while ( i > 0)
	{
		if(num[i] > num[i - 1])
		{
			int ii = num.size() - 1;
			while (ii >= i && num[ii] < num[i - 1]) --ii;

			swap(num[i - 1], num[ii]);
			reverse(num.begin() + i, num.end());
			return;
		}
		--i;
	}
	reverse(num.begin(), num.end());
	return;
}

【leetcode】Next Permutation,布布扣,bubuko.com

【leetcode】Next Permutation

标签：leetcode   面试题   算法   algorithm   numbers   

原文地址：http://blog.csdn.net/shiquxinkong/article/details/29807077