LeetCode/permute.cpp at main · zxk-creator/LeetCode · GitHub

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#include <vector>

using namespace std;

class Solution
{
public:
    vector<vector<int>> permute(vector<int> &nums)
    {
        // 递归思想解决问题
        vector<vector<int>> result;
        vector<int> path;
        int length = nums.size();
        vector<bool> used(length,false);
        // start是啥意思？遍历到第几层了
        backtrack(result, nums, path, length,used);

        return result;
    }

    inline void backtrack(vector<vector<int>> &result,vector<int> &nums,vector<int>& path,int length, vector<bool>& used)
    {
        //终止条件
        if(path.size() == length)
        {
            result.push_back(path);
            return;
        }

        for(int i = 0;i < length;i++)
        {
            //跳过已使用的数组
            if(used[i]) continue;

            used[i] = true;
            path.push_back(nums[i]);
            backtrack(result,nums,path,length,used);

            path.pop_back();
            used[i] = false;
        }
    }
};

int main()
{
    Solution sl;
    vector<int> a = {1,2,3};
    sl.permute(a);

    return 0;
}