LAB 4

Thái Phụng Tuấn - 2453365

using namespace std;

void solution(int);

int main(){

int length;

while (true){

cout << "Type in the length of the array:";

cin >> length;

if (length <= 0)

cout << "The length must be a positive number. Try again."<< endl;

else break;

solution (length);

return 0;

void solution (int a){

float RangeOfNum[a];

float test;

for (int i=1; i<=a; i++){

cout << "Type in the "<<i<<" element of the array:";

cin >> RangeOfNum[i-1];

test = RangeOfNum[0];

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 for (int i=0; i<a; i++){

if (test < RangeOfNum[i]){

test = RangeOfNum[i];

cout << "The largest element in the array is: "<< test;

Exercise 4:

#include <iostream>

using namespace std;

void average(int);

int main()

int length;

while (true){

cout << "Type in the length of the array:";

cin >> length;

if (length <= 0)

cout << "The length must be a positive number. Try again."<< endl;

else break;

average(length);

return 0;

void average(int a){

float RangeOfNum[a];

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 float result;

float sum =0;

for (int i=1; i<=a; i++){

cout << "Type in the "<<i<<" element of the array:";

cin >> RangeOfNum[i-1];

sum += RangeOfNum[i-1];

result = sum/a;

cout << "The average value of the array is: "<< result;

Exercise 5:
#include <iostream>

#include <math.h>

using namespace std;

double solution(double, int);

int main()

{ double base;

cout << "Enter the base (x):";

cin >> base;

int exponent;

cout << "Enter the exponent (n):";

cin >> exponent;

// Xuất ra kết quả

cout << base << " to the power of " <<exponent<<" is " << solution(base,exponent);

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double solution(double a, int b){

double result=1.0;

int abs_b = abs(b);

for (int i=0; i<abs_b; i++){

result *= a;

// Nếu số mũ là âm thì kết quả là nghịch đảo

if (b<0)

result = 1/result;

return result;

Exercise 6:
#include <iostream>

using namespace std;

void solution(int);

int main(){

int length;

while (true){

cout << "Type in the length of the array:";

cin >> length;

if (length <= 0)

cout << "The length must be a positive number. Try again."<< endl;

else break;

solution (length);

return 0;

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void solution (int a){

float RangeOfNum[a];

float test;

for (int i=1; i<=a; i++){

cout << "Type in the "<<i<<" element of the array:";

cin >> RangeOfNum[i-1];

int PostCount = 0; int NeCount = 0;

for (int i=0; i<a; i++){

if (RangeOfNum[i]=0){

continue;

else if (RangeOfNum[i]>0){

PostCount++;

else NeCount++;

cout << "The number of positive value: "<<PostCount << endl;

cout << "The number of negative value: "<< NeCount;

Exercise 7:
#include <iostream>

using namespace std;

void solution(int);

int main(){

int length;

while (true){

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cout << "Type in the order of the array:";

cin >> length;

if (length <= 0)

cout << "The order must be a positive number. Try again."<< endl;

else break;

solution (length);

return 0;

void solution (int n){

int matrix[100][100], transposed[100][100];

cout << "Enter the elements of the matrix row by row:" << endl;

for (int i = 0; i < n; ++i) {

for (int j = 0; j < n; ++j) {

cin >> matrix[i][j];

for (int i = 0; i < n; ++i) {

for (int j = 0; j < n; ++j) {

transposed[j][i] = matrix[i][j];

cout << "\nTransposed Matrix:" << endl;

for (int i = 0; i < n; ++i) {

for (int j = 0; j < n; ++j) {

cout << transposed[i][j] << " ";

cout << endl;

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 }

Exercise 8:
#include <iostream>

#include <math.h>

using namespace std;

int main(){

double ApproximateValue=0.0;

double PreviousValue = 1.0;

int n=0;

const double tolerance = 1.0E-6;

while (abs(ApproximateValue - PreviousValue) >= tolerance){

PreviousValue = ApproximateValue;

double term =(n%2==0? 1.0 : -1.0)/(2*n+1);

ApproximateValue += term;

n++;

double pi= ApproximateValue *4;

cout << "The approximate value of pi is: "<< pi;

return 0;

Exercise 9:
#include <iostream>

#include <math.h>

#define PI 3.141592653589793

using namespace std;

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int main() {

int x=5;

//Start to calculate

for (int i=0; i<17; i++){

//Convert to radians

double RadValue = x*PI/180;

//Tabulate

double Cos = cos(RadValue);

double Sin = sin(RadValue);

double Tan = tan(RadValue);

cout << "The value of cos(" <<x<< ") is: "<<Cos<< endl

<< "The value of sin(" <<x<< ") is: "<< Sin<< endl

<< "The value of tan(" <<x<< ") is: "<< Tan<< endl<<endl;

x+=5;

return 0;

Exercise 10:
#include <iostream>

#include <msth.h>

using namespace std;

double factorial(int n) {

if (n == 0 || n == 1) {

return 1;

return n * factorial(n - 1);

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int main() {

double approximateE = 1.0;

double previousApproximation = 0.0;

double tolerance = 1.0E-6;

int n = 1;

while (abs(approximateE - previousApproximation) >= tolerance) {

previousApproximation = approximateE;

approximateE += 1.0 / factorial(n);

n++; /

cout << "The approximate value of e is: " << approximateE << endl;

return 0;

Exercise 11:
#include <iostream>

using namespace std;

long long fibonacci(int n) {

if (n == 0) return 0;

if (n == 1) return 1;

return fibonacci(n - 1) + fibonacci(n - 2);

int main() {

int n;

cout << "Enter the position (n) of the Fibonacci sequence: ";

cin >> n;

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 if (n < 0) {

cout << "Invalid input! n must be a non-negative integer." << endl;

return 1;

cout << "The Fibonacci number at position " << n << " is: " << fibonacci(n) << endl;

return 0;

Exercise 12:
#include <iostream>

#include <math.h>

//#define PI 3.141592653589793

using namespace std;

void solution(int);

int main(){

int length;

while (true){

cout << "Type in the length of the Fibonacci:";

cin >> length;

if (length <= 0)

cout << "The length must be a positive number. Try again."<< endl;

else break;

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 solution (length);

return 0;

void solution(int a){

int Fibonacci[a];

if (a>0) Fibonacci[0]=0;

if (a>1) Fibonacci[1]=1;

for (int i=2; i<a; i++){

Fibonacci[i]=Fibonacci[i-2]+Fibonacci[i-1];

cout << "The Fibonacci is: ";

for (int i=0; i<a; i++){

cout << Fibonacci[i]<<" ";

Exercise 13:
#include <iostream>

using namespace std;

int main(){

double hourly_rates[5]={9.5, 6.4, 12.5, 5.5, 10.5};

double working_hours[5];

double wages[5];

cout << "Enter the working_hours of 5 staff "<<endl;

for (int i=0; i<5; i++){

cout << "Staff number "<<i+1<<": ";

cin >> working_hours[i];

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 wages[i] = working_hours[i]*hourly_rates[i];

cout << "\n\t" <<"Hourly Rates\t"<< "Working Hours\t"<< "Wages\n"

<<"\t--------------------------------------"<<endl;

for (int i=0; i<5; i++){

cout <<'\t'<< hourly_rates[i]<<"\t\t"<<working_hours[i]<<"\t\t"<<wages[i]<<endl;

return 0;

Exercise 14:
#include <iostream>

#include <cstring>

using namespace std;

int main() {

char str1[100], str2[100], str3[100];

cout << "Enter the first string: ";

cin >> str1;

cout << "Enter the second string: ";

cin >> str2;

cout << "Enter the third string: ";

cin >> str3;

if (strcmp(str1, str2) > 0) {

swap(str1, str2);

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 }

if (strcmp(str2, str3) > 0) {

swap(str2, str3);

if (strcmp(str1, str2) > 0) {

swap(str1, str2);

cout << "\nStrings in alphabetical order:\n";

cout << str1 << endl;

cout << str2 << endl;

cout << str3 << endl;

return 0;

Exercise 15:
#include<iostream>

#include<string>

using namespace std;

const int MAX = 100;

struct student{

char name[20];

long int rollno;

char sex;

float height;

float weight;

};

int main(){

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 student cls[MAX];

int i,n;

cout << " How many names ? \n";

cin >> n;

for( i = 0; i <= n-1; ++i){

cout << "record = "<< i+1 << endl;

cout << "name : "; cin>> cls[i].name;

cout << "rollno : "; cin>> cls[i].rollno;

cout << "sex : "; cin>> cls[i].sex;

cout << "height : "; cin>> cls[i].height;

cout << "weight : "; cin>> cls[i].weight;

cout << endl;

// Task a

cout << "Name\t"<< "Rollno\t"<<"Sex\t"<<"Height\t"<<"Weight\t\n";

for( i = 0; i <= n-1; ++i){

cout <<cls[i].name<<"\t"<< cls[i].rollno <<"\t"<< cls[i].sex <<"\t"<<cls[i].height<<"\

// Task b

float Average_Height, Average_Weight;

float Sum_Height=0.0, Sum_Weight=0.0;

for (int i=0; i<n; i++){

Sum_Height+=cls[i].height;

Sum_Weight+=cls[i].weight;

Average_Weight=Sum_Weight/n;

Average_Height=Sum_Height/n;

cout <<"The average weight is: "<< Average_Weight<<endl;

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cout <<"The average height is: "<< Average_Height<<endl;

return 0;

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