#include <iostream>

using namespace std;

void nhap_mang(float a[], int n) {
	for (int i = 0; i < n; i++) {
		cout<<"a["<<i<<"] = "; cin>>a[i];
	}
}

void hien_thi_nguoc(float a[], int n) {
	cout<<"Mang a theo thu tu nguoc la: "<<endl;
	for (int i = n-1; i >= 0; i--) {
		cout<<"\t"<<a[i];
	}
}

void sap_xep(float a[], int n) {
	int tam;
	for (int i = 0; i < n-1; i++) {
		for (int j = i+1; j < n; j++) {
			if (a[i] < a[j]) {
				tam = a[i];
				a[i] = a[j];
				a[j] = tam;
			}
		}	
	}
	cout<<"\nMang sau khi sap xep: "<<endl;
	for (int i = 0; i < n; i++) cout<<"\t"<<a[i];
}

void chen_phan_tu(float a[], int &n, int k, float x) {
	for (int i = n-1; i >= k; i--) {
		a[i+1] = a[i];
	}
	a[k] = x;
	n++;
}

void nhap_x(float a[], int n) {
	float x;
	cout<<"\nNhap x: "; cin>>x;
	for (int i = 0; i < n; i++) {
		if (a[i] <= x) {
			chen_phan_tu(a, n, i, x);
			break;
		}
	}
	cout<<"Mang sau khi chen phan tu x "<<endl;
	for (int i = 0; i < n; i++) cout<<"\t"<<a[i];
}

int main() {
	int n;
	float a[30];
	do {
		cout<<"Nhap n: "; cin>>n;
		if (n < 1 || n > 30) cout<<"Nhap so nguyen 1 <= n <= 30"<<endl;
	} while (n < 1 || n > 30);
	nhap_mang(a,n);
	hien_thi_nguoc(a,n);
	sap_xep(a,n);
	nhap_x(a,n);
	return 0;
}