leetcode_384

Shuffle a set of numbers without duplicates.

Example:

// Init an array with set 1, 2, and 3. int[] nums = {1,2,3}; Solution solution = new Solution(nums);

// Shuffle the array [1,2,3] and return its result. Any permutation of [1,2,3] must equally likely to be returned. solution.shuffle();

// Resets the array back to its original configuration [1,2,3]. solution.reset();

// Returns the random shuffling of array [1,2,3]. solution.shuffle();

Solutions

1. Fisher-Yates

class Solution {
public:
    vector<int> nums;
    Solution(vector<int>& nums) : nums(nums) {

    }

    /** Resets the array to its original configuration and return it. */
    vector<int> reset() {
        return nums;
    }

    /** Returns a random shuffling of the array. */
    vector<int> shuffle() {
        vector<int> nums(this->nums);
        int len = nums.size();
        for (int i = 0; i < len; i++)
            swap(nums[i], nums[i + (rand() % (len - i))]);
        return nums;
    }
};

/**
 * 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();
 */