Create L2-011 玩转二叉树 (25 分).cpp

GPLT/CPP/L2-011 玩转二叉树 (25 分).cpp

@@ -0,0 +1,40 @@
+#include <iostream>
+#include <vector>
+using namespace std;
+
+vector<int> InOrder, PreOrder, Level(10000, -1);
+// 递归层次遍历 
+void getLevel(int root, int start, int end, int index);
+
+int main(){
+	int n, cnt = 0;
+	cin >> n;
+	InOrder.resize(n);
+	PreOrder.resize(n);
+	//Level.resize(n);
+	//vector<int> InOrder(n), PreOrder(n), Level(n);
+	for(int i = 0; i < n; i++)
+		cin >> InOrder[i];
+	for(int i = 0; i < n; i++)
+		cin >> PreOrder[i];
+	getLevel(0, 0, n-1, 0);
+	for(int i = 0; i < Level.size(); i++){
+		if(Level[i] != -1 && cnt != n - 1){
+			cout << Level[i] << " ";
+			cnt++;
+		}else if(Level[i] != -1){
+			cout << Level[i];
+			break;
+		}
+	}
+	return 0; 
+}
+
+void getLevel(int root, int start, int end, int index){
+	if(start > end) return ;
+	int i = start;
+	while(i < end && InOrder[i] != PreOrder[root]) i++;
+	Level[index] = PreOrder[root];
+	getLevel(root + 1, start, i - 1, 2 * index + 2);
+	getLevel(root + 1 + i - start, i + 1, end, 2 * index + 1);
+}