力扣 题目46- 全排列+47-全排列 II

题目

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题解

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46.

一看这个题目 发现和 力扣 题目31-- 下一个排列 类似 一个是找下一个 一个是找全部

那么我们把一开始nums进行排序从小到大 然后循环31题的题解 加入vector<vector<int>> res; 如果i为-1则退出 循环即可

47.同上

代码

46

#include<iostream>
#include<vector>
#include<map>
#include<algorithm> 
using namespace std;
class Solution {
public:
    vector<vector<int>> permute(vector<int>& nums) {
        sort(nums.begin(), nums.end());
        vector<vector<int>> res;
        //加个循环
        while (true)
        {
            res.push_back(nums);
            map<int, int>additional;
            int i = nums.size() - 1;
            for (; i > -1; i--) {
                additional.insert(pair<int, int>(nums[i], i));
                if (i > 0 && nums[i] > nums[i - 1]) {
                    for (map<int, int>::iterator it = additional.begin(); it != additional.end(); it++)
                    {
                        if (nums[i - 1] < it->first) {
                            nums[it->second] = nums[i - 1];
                            nums[i - 1] = it->first;
                            break;
                        }
                    }
                    break;
                }
            }
            if (i > -1) {
                sort(nums.begin() + i, nums.end());
            }
            else {
                break;
            }
        }
        return res;
    }
};
int main() {
    Solution sol;
    vector<int> nums = { 1,2,3,4 };
    vector<vector<int>> res = sol.permute(nums);
    for (int i = 0; i < res.size(); i++) {
        for (int j = 0; j < res[i].size(); j++) {
            cout << res[i][j];
        }
        cout << endl;
    }

}

47.

#include<iostream>
#include<vector>
#include<map>
#include<algorithm> 
using namespace std;
class Solution {
public:
    vector<vector<int>> permuteUnique(vector<int>& nums) {
        sort(nums.begin(), nums.end());
        vector<vector<int>> res;
        //加个循环
        while (true)
        {
            res.push_back(nums);
            map<int, int>additional;
            int i = nums.size() - 1;
            for (; i > -1; i--) {
                additional.insert(pair<int, int>(nums[i], i));
                if (i > 0 && nums[i] > nums[i - 1]) {
                    for (map<int, int>::iterator it = additional.begin(); it != additional.end(); it++)
                    {
                        if (nums[i - 1] < it->first) {
                            nums[it->second] = nums[i - 1];
                            nums[i - 1] = it->first;
                            break;
                        }
                    }
                    break;
                }
            }
            if (i > -1) {
                sort(nums.begin() + i, nums.end());
            }
            else {
                break;
            }
        }
        return res;
    }
};
int main() {
    Solution sol;
    vector<int> nums = { 1,2,3,4 };
    vector<vector<int>> res = sol.permuteUnique(nums);
    for (int i = 0; i < res.size(); i++) {
        for (int j = 0; j < res[i].size(); j++) {
            cout << res[i][j];
        }
        cout << endl;
    }

}