使用Fisher-Yates 洗牌算法实现random_shuffle函数

Posted 2021-12-17 Harris-H

使用Fisher-Yates 洗牌算法实现random_shuffle函数

class Solution 
public:
    Solution(vector<int>& nums) 
        this->nums = nums;
        this->original.resize(nums.size());
        copy(nums.begin(), nums.end(), original.begin());
    
    
    vector<int> reset() 
        copy(original.begin(), original.end(), nums.begin());
        return nums;
    
    
    vector<int> shuffle() 
        for (int i = 0; i < nums.size(); ++i) 
            int j = i + rand() % (nums.size() - i);
            swap(nums[i], nums[j]);
        
        return nums;
    
private:
    vector<int> nums;
    vector<int> original;
;

直接调用random_suffle 函数实现

class Solution 
public:
    vector<int> b;
    Solution(vector<int>& a) 
        b=a;
    
    
    vector<int> reset() 
        return b;
    
    
    vector<int> shuffle() 
        vector<int> c = b;
        random_shuffle(c.begin(),c.end());
        return c;
    
;

/**
 * Your Solution object will be instantiated and called as such:
 * Solution* obj = new Solution(nums);
 * vector<int> param_1 = obj->reset();
 * vector<int> param_2 = obj->shuffle();
 */