【LeetCode热题100】【技巧】下一个排列

class Solution {
public:
    void nextPermutation(vector<int> &nums) {
        int small = nums.size() - 2;
        while (small >= 0 && nums[small] >= nums[small + 1])
            small--;
        int big = nums.size() - 1;
        if (small >= 0) {  // 交换小的和较大的
            while (nums[big] <= nums[small])
                big--;
            swap(nums[big], nums[small]);
        }
        reverse(nums.begin() + small + 1, nums.end());
    }
};