[LeetCode]384. Shuffle an Array

题目描述

思路

洗牌算法
逆序遍历数组，对于当前位置的数，随机生成一个0-当前位置的表示位置的数，交换二者

代码

#include <iostream>#include <vector>#include <algorithm>using namespace std;class Solution {public:    Solution(vector<int> nums) {        len = nums.size();        this->nums.resize(len);        source.resize(len);        if (len) {            memcpy(&this->nums[0], &nums[0], len * sizeof(int));            memcpy(&source[0], &nums[0], len * sizeof(int));        }    }    vector<int> reset() {                   return source;    }    vector<int> shuffle() {        for (int i = len - 1; i >= 0; i--) {            swap(nums[i], nums[rand() % (i + 1)]);        }        return nums;    }private:    vector<int> nums;    vector<int> source;    int len;};int main() {    vector<int> nums = {1, 2, 3, 4, 6, 9};    Solution s(nums);    vector<int> random = s.shuffle();    vector<int> source = s.reset();    cout << "nums:" << endl;    for (auto p : nums) {        cout << p << " ";    }    cout << endl;    cout << "random:" << endl;    for (auto p : random) {        cout << p << " ";    }    cout << endl;    cout << "source:" << endl;    for (auto p : source) {        cout << p << " ";    }    cout << endl;    system("pause");    return 0;}