Shuffle an Array – LeetCode Solution Java , Python 3, Python 2 , C , C++, Best and Optimal Solutions , All you need.
Given an integer array nums
, design an algorithm to randomly shuffle the array. All permutations of the array should be equally likely as a result of the shuffling.
Implement the Solution
class:
Solution(int[] nums)
Initializes the object with the integer arraynums
.int[] reset()
Resets the array to its original configuration and returns it.int[] shuffle()
Returns a random shuffling of the array.
Example 1:
Input ["Solution", "shuffle", "reset", "shuffle"] [[[1, 2, 3]], [], [], []] Output [null, [3, 1, 2], [1, 2, 3], [1, 3, 2]] Explanation Solution solution = new Solution([1, 2, 3]); solution.shuffle(); // Shuffle the array [1,2,3] and return its result. // Any permutation of [1,2,3] must be equally likely to be returned. // Example: return [3, 1, 2] solution.reset(); // Resets the array back to its original configuration [1,2,3]. Return [1, 2, 3] solution.shuffle(); // Returns the random shuffling of array [1,2,3]. Example: return [1, 3, 2]
Constraints:
1 <= nums.length <= 50
-106 <= nums[i] <= 106
- All the elements of
nums
are unique. - At most
104
calls in total will be made toreset
andshuffle
.
C++ Shuffle an Array LeetCode Solution
class Solution {
public:
vector<int>temp;
vector<int>temp2;
Solution(vector<int>& nums) {
temp=nums;
temp2=nums;
}
vector<int> reset() {
return temp;
}
vector<int> shuffle() {
int random=rand()%temp.size();
swap(temp2[random],temp2[0]);
return temp2;
}
};
Java Shuffle an Array LeetCode Solution
int[] nums;
Random r;
int[] orig;
public Solution(int[] nums) {
orig = nums.clone();
r = new Random();
this.nums = nums;
}
public int[] reset() {
return orig;
}
public int[] shuffle() {
for(int i = 0; i < nums.length; i++) {
int random = getRand(i, nums.length - 1);
int tmp = nums[i];
nums[i] = nums[random];
nums[random] = tmp;
}
return nums;
}
//get a random number among [i, j].
private int getRand(int i, int j) {
return i + r.nextInt(j - i + 1);
}
Python 3 Shuffle an Array LeetCode Solution
class Solution(object):
def __init__(self, nums):
self.nums_array = nums
self.shuffle_nums_array = nums[:]
def reset(self):
return self.nums_array
def shuffle(self):
random.shuffle(self.shuffle_nums_array)
return self.shuffle_nums_array
Array-1180
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Eulerian Circuit-3
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