tags: Weekly Contest

Weekly Contest 406

3216. Lexicographically Smallest String After a Swap (Easy)

限制 :

• 2 <= s.length <= 100
• s consists only of digits.

時間複雜度:

$O(n)$

空間複雜度:

$O(1)$

程式碼:

class Solution {
public:
    string getSmallestString(string s) {
        for (int i = 0; i < s.size() - 1; i++) {
            if (s[i] % 2 == s[i + 1] % 2 && s[i] > s[i + 1]) {
                swap(s[i], s[i + 1]);
                break;
            }
        }
        return s;
    }
};

3217. Delete Nodes From Linked List Present in Array (Medium)

限制 :

• 1 <= nums.length <= 105
• 1 <= nums[i] <= 105
• All elements in nums are unique.
• The number of nodes in the given list is in the range [1, 105].
• 1 <= Node.val <=105
• The input is generated such that there is at least one node in the linked list that has a value not present in nums.

Solution

時間複雜度:

$O()$

空間複雜度:

$O()$

程式碼:

class Solution {
public:
    ListNode* modifiedList(vector<int>& nums, ListNode* head) {
        unordered_set<int> numss(nums.begin(), nums.end());
        while (numss.find(head-> val) != numss.end()) {
            head = head->next;
        }
        ListNode* left = head;
        while (left && left->next != nullptr) {
            ListNode* right = left->next;
            while (right && numss.find(right->val) != numss.end()) {
                left->next = right->next;
                right = right->next;
            }
            left = right;
        }
        return head;
    }
};

3(Medium)

限制 :

• 104

時間複雜度:

$O()$

空間複雜度:

$O()$

程式碼:

4(Hard)

限制 :

• 104

時間複雜度:

$O()$

空間複雜度:

$O()$

程式碼: