46. Permutations
Đề Bài
Given an array nums of distinct integers, return all the possible permutations. You can return the answer in any order.
Example 1:
Input: nums = [1,2,3] Output: [[1,2,3],[1,3,2],[2,1,3],[2,3,1],[3,1,2],[3,2,1]]
Example 2:
Input: nums = [0,1] Output: [[0,1],[1,0]]
Example 3:
Input: nums = [1] Output: [[1]]
Constraints:
1 <= nums.length <= 6-10 <= nums[i] <= 10- All the integers of
numsare unique.
Thuật Toán & Kỹ Thuật
⏱️ Thời gian
O(V+E)
💾 Không gian
O(V)
Lời Giải
C++
0046-permutations.cpp
class Solution {
private:
vector<int> path, nums;
vector<bool> visited;
vector<vector<int>> ans;
int n;
public:
void dfs(int cnt) {
if (cnt == n) {
ans.push_back(path);
return;
}
for (int i = 0; i < n; ++i) {
if (!visited[i]) {
path.push_back(nums[i]);
visited[i] = true;
dfs(cnt + 1);
path.pop_back();
visited[i] = false;
}
}
}
vector<vector<int>> permute(vector<int>& nums) {
this->n = nums.size();
visited.resize(n, false);
this->nums = nums;
dfs(0);
return ans;
}
};