Merge pull request #83 from AlgoLeadMe/24-InSange

24-InSange

InSange/BFS/1068.cpp

@@ -0,0 +1,106 @@
+#include <iostream>
+#include <vector>
+#include <queue>
+
+using namespace std;
+
+struct Node
+{
+	Node()
+	{
+		parent = nullptr;
+		leafNode = true;
+	}
+
+	vector<int> childs;
+	Node* parent;
+	bool leafNode;
+};
+
+vector<Node*> nodes;
+int N, ans = 0, rIndex;
+
+void NodeUpdate(Node* curNode)
+{
+	for (auto child : curNode->childs)
+	{
+		if (nodes[child] != nullptr)
+		{
+			curNode->leafNode = false;
+			return;
+		}
+	}
+	curNode->leafNode = true;
+}
+
+void Solve()
+{
+	cin >> N;
+
+	for (int i = 0; i < N; i++)
+	{
+		Node* node = new Node();
+
+		nodes.push_back(node);
+	}
+	int root_index = 0;
+
+	for(int i = 0; i < N; i++)
+	{
+		int p;
+		cin >> p;
+
+		if (p == -1)
+		{
+			root_index = i;
+			continue;
+		}
+		nodes[i]->parent = nodes[p];
+		nodes[i]->parent->childs.push_back(i);
+		if (nodes[i]->parent)
+		{
+			NodeUpdate(nodes[i]->parent);
+		}
+	}
+
+	cin >> rIndex;
+	if (rIndex == root_index)	// Á¦°Å µÈ°Ô ·çÆ®¶ó¸é
+	{
+		cout << ans << "\n";
+		return;
+	}
+	Node* parentNode = nodes[rIndex]->parent;
+	delete nodes[rIndex];
+	nodes[rIndex] = nullptr;
+	NodeUpdate(parentNode);
+
+	queue<Node*> q;
+	q.push(nodes[root_index]);
+
+	while (!q.empty())
+	{
+		Node* cur = q.front();
+		q.pop();
+
+		if (cur->leafNode) ans++;
+		for (auto index : cur->childs)
+		{
+			if (nodes[index] != nullptr)
+			{
+				q.push(nodes[index]);
+			}
+		}
+	}
+
+	cout << ans;
+}
+
+int main()
+{
+	cin.tie(nullptr);
+	ios::sync_with_stdio(false);
+
+	Solve();
+
+	return 0;
+}

InSange/README.md

@@ -25,6 +25,7 @@
 | 21차시 | 2024.07.21 |  그리디  | [Find Valid Matrix Given Row and Column Sums](https://leetcode.com/problems/find-valid-matrix-given-row-and-column-sums/)  | [#21](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/75)]
 | 22차시 | 2024.07.31 |  DP  | [Filling Bookcase Shelves](https://leetcode.com/problems/filling-bookcase-shelves/)  | [#22](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/81)]
 | 23차시 | 2024.08.03 |  슬라이딩 윈도우  | [Minimum Swaps to Group All 1's Together 2](https://leetcode.com/problems/minimum-swaps-to-group-all-1s-together-ii/)  | [#23](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/82)]
+| 24차시 | 2024.08.04 |  BFS  | [트리](https://www.acmicpc.net/problem/1068)  | [#24](https://github.com/AlgoLeadMe/AlgoLeadMe-8/pull/83)]
 ---
 
 https://leetcode.com/problems/robot-collisions/