Renewed Structure

Algorithm/Recursion/P27_All_Sorted.cpp

@@ -0,0 +1,38 @@
+//For a,b,c we have sort abc acb bac bca cab cba(6 kinds) This Program is to sort all of the kinds
+#include <iostream>
+using namespace std;
+// 递减n叉树
+// 可能需要包展开，这里先不写，先以3个为主
+template<typename T>
+T* sort(int n, int l, T* tmp, bool* used, T* arr){
+	if(n == l){
+		cout << "[";
+		for(int i = 0;i < n; i++){
+		cout << tmp[i] <<" ";
+		}
+		cout << "]" << endl;
+	}
+
+	for(int i = 0;i < l; i++){
+		if(used[i] == false){
+			tmp[n] = arr[i];
+			used[i] = true;
+			sort(n + 1, l, tmp, used, arr);
+			used[i] = false; //是否可以删除？不可以，回溯本节点要用
+		}
+	}
+}
+
+
+int main() {
+	int n;
+	cin >> n;
+	int* tmp = new int[n];
+	int* arr = new int[n];
+	for(int i = 0;i < n; i++){
+		cin >> arr[i];
+	}
+	bool* used = new bool[n];
+	sort(0, n, tmp, used, arr);
+	return 0;
+}

Algorithm/Recursion/P28_19_n!.cpp

@@ -0,0 +1,12 @@
+#include <iostream>
+using namespace std;
+int jc(int n){
+    if(n > 0)
+        return jc(n - 1)*n;
+    return 1;
+}
+
+int main(){
+    cout << jc(10) << endl;
+    return 0;
+}

Algorithm/Recursion/P28_20_Feb.cpp

@@ -0,0 +1,15 @@
+#include <iostream>
+using namespace std;
+
+int feb(int n){
+	if(n > 1)
+		return feb(n - 1) + feb(n - 2);
+	return 1;
+}
+
+int main(){
+	for(int i = 1;i < 10; i++){
+		cout << feb(i) << endl;
+	}
+	return 0;
+} 

Algorithm/Recursion/P29_21_ComplexFunc.cpp

@@ -0,0 +1,14 @@
+#include <iostream>
+using namespace std;
+
+int cf(int n){
+	if(n%2 == 1)
+		return cf(3*n + 1);
+	if(n%2 == 0)
+		return n / 2;
+}
+
+int main(){
+	cout << cf(5) << " "<< cf(6) << " " << cf(7) << endl;
+	return 0;
+}

Algorithm/Recursion/P29_22_Ackermann.cpp

@@ -0,0 +1,21 @@
+#include <iostream>
+#include <cmath>
+using namespace std;
+
+int ack(int i, int j){
+	if(i == 1 && j >= 1)
+		return pow(2,j);
+	if(i >=2 && j == 1)
+		return ack(i - 1, 2);
+	if(i >= 2 && j >= 2)
+		return ack(i - 1, ack(i, j - 1));
+	return 0;
+}
+
+int main(){
+	cout << "1,2: " << ack(1,2) << endl;
+	cout << "2,1: " << ack(2,1) << endl;
+	cout << "2,2: " << ack(2,2) << endl;
+	cout << "1,3: " << ack(1,3) << endl; 
+	return 0;
+}

Algorithm/Recursion/P29_23_GCD.cpp

@@ -0,0 +1,20 @@
+#include <iostream>
+#include <cmath>
+using namespace std;
+
+int gcd(int x, int y){
+	x = abs(x);
+	y = abs(y);
+	if(y == 0)
+		return x;
+	if(y > 0)
+		return gcd(y, x % y);
+	return 0;
+}
+
+int main(){
+	cout << gcd(20 ,30) << endl;
+	cout << gcd(112, 42) << endl;
+	cout << gcd(-112,42) << endl;
+	return 0;
+}

Algorithm/Recursion/P29_24_checkfunc.cpp

@@ -0,0 +1,33 @@
+/*
+Request: Code a template module to check if x is in a[0:n-1]
+*/
+
+#include <iostream>
+#include <string>
+using namespace std;
+
+template <class T>
+bool chk(T x, T* a, int n){
+	if(n > 1 && x != a[n - 1])
+		return chk(x,a,n-1);
+	if(n == 1 && x != a[0])
+		return false;
+	return true;
+}
+
+int main(){
+	int a[] = {2,3,4,5,6,7,9};
+	cout << chk(2,a,7) << " " << chk(1,a,7)<<endl;
+	return 0;
+}
+
+/*
+AI wrote like this:
+
+template <class T>
+bool chk(T x, T* a, int n) {
+    if (n <= 0) return false;
+    if (a[n - 1] == x) return true;
+    return chk(x, a, n - 1);
+}
+*/

Algorithm/Recursion/P29_25_SubsetGen.cpp

@@ -0,0 +1,51 @@
+//Generate subset
+#include <iostream>
+#include <cmath>
+using namespace std;
+//m: 本次递归选原数组第几个
+//n: 本次递归数组长度
+//l: 给定数组长度
+template <class T>
+T* sub(int m ,int n, int l, T* x, T* tmp){
+	if(m == l)
+	{
+
+		cout << "[ ";
+		for(int i = 0; i < n; i++){
+			cout << tmp[i] << " ";
+		}
+		cout << " ]" << endl;
+		return tmp;
+	
+	}
+	//不选a[i]
+	sub(m + 1, n, l, x, tmp);
+
+	//选a[i]
+	tmp[n] = x[m];
+	sub(m + 1, n + 1, l, x, tmp);
+
+
+}
+
+int main(){
+	//cin >> n;
+	int n = 5;
+	int num = pow(2 ,n);
+	double** p;
+       	p = new double* [num];
+	for(int i = 0; i < num ; i++){
+		p[i] = new double[n];
+	}
+	double* tmp = new double[n];
+	double arr[] = {1, 2, 3, 4, 5};
+	sub(0, 0, 5, arr, tmp);
+	return 0;
+}
+
+
+
+
+
+
+