31-InSange

InSange/DFS/2097 Valid Arrangement of Pairs.cpp

@@ -0,0 +1,64 @@
+#include <unordered_map>
+#include <deque>
+#include <vector>
+
+using namespace std;
+
+class Solution {
+public:
+    unordered_map<int, deque<int>> nodes;
+    unordered_map<int, int> inDegree;
+    unordered_map<int, int> outDegree;
+
+    vector<int> result;
+
+    void DFS(int index)
+    {
+        while (!nodes[index].empty())
+        {
+            int nextNode = nodes[index].front();
+            nodes[index].pop_front();
+            DFS(nextNode);
+        }
+        result.push_back(index); // �ᱹ. ��� ������ �湮�ߴٸ�. �� ������ִ� ��忡 �湮�ߴٸ� ������ ��ΰ� �Ųٷ� �̾����� ��.
+    }
+
+    vector<vector<int>> validArrangement(vector<vector<int>>& pairs) {
+        for (const vector<int>& pair : pairs)
+        {
+            int depart = pair[0];
+            int dest = pair[1];
+
+            nodes[depart].push_back(dest);
+            inDegree[dest]++;
+            outDegree[depart]++;
+        }
+
+        int startNode = -1;
+
+        for (const auto& degree : outDegree)
+        {
+            int curNode = degree.first;
+            if (outDegree[curNode] == inDegree[curNode] + 1) // ���� ��忡�� ������� ���� ���� ������ ������ ���� + 1�� ���. �� ���� ���� ���� �ٽ� �ش� ��带 ���ľ� ��� ��带 �湮�� �� ����.
+            {
+                startNode = curNode;
+                break;
+            }
+        }
+
+        if (startNode == -1) // ��� ��带 �߰� ���ߴٸ� ��� ���� ���� �ϳ��� ����, �������� �����ϰ� ������ ��
+        {
+            startNode = pairs[0][0];
+        }
+
+        DFS(startNode);
+
+        vector<vector<int>> ans;
+        for (int i = result.size() - 1; i > 0; i--)
+        {
+            ans.push_back({ result[i], result[i - 1] }); // ������� �������� �Ųٷ� ����
+        }
+
+        return ans;
+    }
+};

InSange/README.md

@@ -29,6 +29,11 @@
 | 25차시 | 2024.08.10 |  BFS  | [Minimum Height Trees](https://leetcode.com/problems/minimum-height-trees/)  | [#25](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/87)]
 | 26차시 | 2024.08.11 |  수학  | [Magic Squares In Grid](https://leetcode.com/problems/magic-squares-in-grid/)  | [#26](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/89)]
 | 27차시 | 2024.08.17 |  문자열  | [Number of Senior Citizens](https://leetcode.com/problems/number-of-senior-citizens/)  | [#27](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/91)]
+| 28차시 | 2024.08.21 |  백트래킹 | [월드컵](https://www.acmicpc.net/problem/6987)  | [#28](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/94)]
+| 29차시 | 2024.08.25 |  문자열 | [Find the Closest Palindrome](https://leetcode.com/problems/find-the-closest-palindrome/)  | [#29](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/98)]
+| 30차시 | 2024.09.06 |  문자열 | [Delete Nodes From Linked List Present in Array](https://leetcode.com/problems/delete-nodes-from-linked-list-present-in-array/)  | [#30](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/100)]
+| 31차시 | 2024.12.01 |  DFS | [Valid Arrangement of Pairs](https://leetcode.com/problems/valid-arrangement-of-pairs/)  | [#31](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/101)]
 ---
 
 https://leetcode.com/problems/robot-collisions/
+Find the Closest Palindrome

InSange/문자열/564_Find the Closest Palindrome.cpp

@@ -0,0 +1,74 @@
+#include <iostream>
+#include <string>
+
+using namespace std;
+
+class Solution {
+public:
+    long long Convert(long long& num)
+    {
+        string s = to_string(num);
+        int n = s.length();
+        int l = (n - 1) / 2;
+        int r = n / 2;
+        while (l >= 0) s[r++] = s[l--];
+        return stoll(s);
+    }
+
+    long long UpPal(long long num)
+    {
+        long long left = 0;
+        long long right = num;
+        long long ans = INT_MIN;
+
+        while (left <= right)
+        {
+            long long mid = (right + left) / 2;
+            long long palin = Convert(mid);
+            if (palin < num)
+            {
+                ans = palin;
+                left = mid + 1;
+            }
+            else
+            {
+                right = mid - 1;
+            }
+        }
+
+        return ans;
+    }
+
+    long long DownPal(long long num)
+    {
+        long long left = num;
+        long long right = 1e18;
+        long long ans = INT_MIN;
+
+        while (left <= right) {
+            long long mid = (right + left) / 2;
+            long long palin = Convert(mid);
+            if (palin > num)
+            {
+                ans = palin;
+                right = mid - 1;
+            }
+            else
+            {
+                left = mid + 1;
+            }
+        }
+
+        return ans;
+    }
+
+    string nearestPalindromic(string n) {
+        long long num = stoll(n);
+        long long a = UpPal(num);
+        long long b = DownPal(num);
+
+        if (abs(a - num) <= abs(b - num)) return to_string(a);
+
+        return to_string(b);
+    }
+};

InSange/백트래킹/6987.cpp

@@ -0,0 +1,91 @@
+#include <iostream>
+#include <vector>
+
+using namespace std;
+
+vector<vector<int>> record;
+int t;
+bool draw_flag, flag;
+vector<pair<int, int>> game = { {0, 1}, {0, 2}, {0, 3}, {0, 4}, {0, 5},
+													 {1, 2}, {1, 3}, {1, 4}, {1, 5},
+													 {2, 3}, {2, 4}, {2, 5},
+													 {3, 4}, {3, 5},
+													 {4, 5} };
+
+bool CheckPlay(int round)
+{
+	if (round == 15)
+	{
+		for (int i = 0; i < 6; i++)
+		{
+			for (int j = 0; j < 3; j++)
+			{
+				if (record[i][j]) return false;
+			}
+		}
+		return true;
+	}
+
+	int firstTeam, secondTeam;
+	firstTeam = game[round].first;
+	secondTeam = game[round].second;
+
+	if (record[firstTeam][0] && record[secondTeam][2])	// first team win, second team lose
+	{
+		--record[firstTeam][0];
+		--record[secondTeam][2];
+		if (CheckPlay(round + 1)) return true;
+		++record[firstTeam][0];
+		++record[secondTeam][2];
+	}
+
+	if (record[firstTeam][1] && record[secondTeam][1])	// first team draw, second team draw
+	{
+		--record[firstTeam][1];
+		--record[secondTeam][1];
+		if (CheckPlay(round + 1)) return true;
+		++record[firstTeam][1];
+		++record[secondTeam][1];
+	}
+
+	if (record[firstTeam][2] && record[secondTeam][0])	// first team lose, second team win
+	{
+		--record[firstTeam][2];
+		--record[secondTeam][0];
+		if (CheckPlay(round + 1)) return true;
+		++record[firstTeam][2];
+		++record[secondTeam][0];
+	}
+
+	return false;
+}
+
+void Solve()
+{
+	record.assign(6, vector<int>(3, 0));
+	t = 4;
+
+	while (t--)
+	{
+		for (int i = 0; i < 6; i++)
+		{
+			for (int j = 0; j < 3; j++)
+			{
+				cin >> record[i][j];
+			}
+		}
+
+		if (CheckPlay(0)) cout << 1 << " ";
+		else cout << 0 << " ";
+	}
+}
+
+int main()
+{
+	ios::sync_with_stdio(false);
+	cin.tie(nullptr);
+
+	Solve();
+
+	return 0;
+}

InSange/연결 리스트/3217_Delete Nodes From Linked List Present in Array.cpp

@@ -0,0 +1,35 @@
+#include <vector>
+#include <unordered_map>
+
+using namespace std;
+
+
+struct ListNode {
+    int val;
+    ListNode* next;
+    ListNode() : val(0), next(nullptr) {}
+    ListNode(int x) : val(x), next(nullptr) {}
+    ListNode(int x, ListNode* next) : val(x), next(next) {}
+};
+
+class Solution {
+public:
+    ListNode* modifiedList(vector<int>& nums, ListNode* head) {
+        ListNode* removeList = new ListNode();
+        ListNode* removeHead;
+        unordered_map<int, bool> um;
+
+        for (int& val : nums) um[val] = true;
+
+        removeList->next = head;
+        removeHead = removeList;
+
+        while (removeHead->next)
+        {
+            if (um[removeHead->next->val] == true) removeHead->next = removeHead->next->next;
+            else removeHead = removeHead->next;
+        }
+
+        return removeList->next;
+    }
+};