public static void Exercitiul11()
{
Console.WriteLine(" 11. Write a function to print nth number in Fibonacci series?");
int nr = 0;
nr = Metoda.PrelParamInt();
List <int> lstFibonacci = new List <int>();
lstFibonacci = Metoda.FibIterativ(nr);
Metoda.AfisareList(lstFibonacci, " Fibonacci numbers are: ");
int z = 0;
for (int x = 0; x < lstFibonacci.Count; x++)
{
if (x == nr - 1)
{
z = lstFibonacci[x];
}
}
Console.WriteLine(" Al {0}-lea numar din sirul lui Fibonacci este: {1}", nr.ToString(), z.ToString());
}
public static List <string> EliminaDuplicate(string[] arr)//returneaza lista cu valorile distincte
{
List <string> lstUnice = new List <string>();
for (int x = 0; x < arr.Length; x++)
{
int count = 0;
if (Metoda.Exista(arr[x].ToString(), lstUnice) == true)//(lstUnice.Contains(newArr[x]))
{
continue;
}
lstUnice.Add(arr[x].ToString());
for (int y = 0; y < arr.Length; y++)
{
if (arr[x].ToString() == arr[y].ToString())
{
count++;
}
}
if (count == 1)
{
Console.WriteLine(" Item {0} is unique.", arr[x].ToString());
}
if (count != 1)
{
Console.WriteLine(" Item {0} appears {1} times.", arr[x], count.ToString());//cum fac sa nu mai afiseze de 'n' ori ca un nr anume se repeta de 'n' ori?
}
//lstUnice.Remove(arr[x]);//daca e sa scot aceasta linie si acoladele de la if si sa ramana doar cw ca la if-ul anterior, se rezolva pb, insa am nevoie de Remove...
}
return(lstUnice);
}
public static void Exercitiul18()
{
Console.WriteLine(" Ex.18. Write code to reverse a linked list, if you able to do it using loops,");
Console.WriteLine(" try to solve with recursion?");
Console.WriteLine(" Enter some letters to reverse them: ");
string litere = Console.ReadLine();
string[] arrLitere = new string[litere.Length];
arrLitere = Metoda.GenStrArray(litere);
LinkedList <string> lstCuvinte = new LinkedList <string>(arrLitere);
Console.WriteLine(" The initial list of the letters you entered...");
Metoda.AfisareLkList(lstCuvinte);
LinkedList <string> lstPeDos = new LinkedList <string>();
for (int i = 0; i < arrLitere.Length; i++)
{
lstPeDos.AddLast(arrLitere[arrLitere.Length - 1 - i]);
}
Console.WriteLine(" The reversed list of the letters...");
Metoda.AfisareLkList(lstPeDos);
//varianta recursiva va trebui sa o discutam la curs
}
public static void Exercitiul12()
{
Console.WriteLine(" 12. Write a function to count a total number of set bits in a 32 bit Integer?");
Console.WriteLine(" Enter an integer:");
int numar = Convert.ToInt32(Console.ReadLine());
int counter = 0;
List <int> binar = new List <int>();
while (numar > 0)
{
//Console.Write("{0} ", (numar % 2).ToString());
binar.Add(numar % 2);
if ((numar % 2) == 1)
{
counter++;
}
numar = numar / 2;
}
binar.Reverse();
Metoda.AfisareList(binar, " Binary form of the number you entered is: ");
Console.WriteLine("\n");
Console.WriteLine(" Total number of set bits is: {1}", numar.ToString(), counter.ToString());
}
public static void Exercitiul9()
{
Console.WriteLine(" Ex.9. How to merge two sorted linked list?");
int lungime, valMax;
Metoda.PrelParamInt(out lungime, out valMax);//preluam lungimea si val maxima de la utilizator
List <int> list1 = new List <int>();
list1 = Metoda.GenIntList(lungime, valMax);//generam prima lista cu elem aleatorii
List <int> list2 = new List <int>();
list2 = Metoda.GenIntList(lungime, valMax);//generam a doua lista cu elem aleatorii
Metoda.AfisareList(list1, " List1 elements: ");
Metoda.AfisareList(list2, " List2 elements: ");
int[] arrList1 = new int[list1.Count]; //initializam 2 array-uri pentru a copia in ele elementele celor 2 liste de mai sus
int[] arrList2 = new int[list2.Count]; //ca sa putem folosi metoda 'EliminaDuplicate'
for (int i = 0; i < list1.Count; i++)//populam primul array cu elem. din prima lista
{
arrList1[i] = list1[i];
}
//Metoda.AfisareArr(arrList1);
for (int i = 0; i < list2.Count; i++)//populam al doilea array cu elem. din a doua lista
{
arrList2[i] = list2[i];
}
//Metoda.AfisareArr(arrList2);
List <int> listaUnice1 = new List <int>();//initializam 2 liste in care sa stocam valorile unice
List <int> listaUnice2 = new List <int>();
listaUnice1 = Metoda.EliminaDuplicate(arrList1); //populam prima lista cu unicate, folosind metoda 'EliminaDuplicate'
listaUnice2 = Metoda.EliminaDuplicate(arrList2); //populam a doua lista cu unicate, folosind metoda 'EliminaDuplicate'
Metoda.AfisareList(listaUnice1, " Lista unice 1: ");
Metoda.AfisareList(listaUnice2, " Lista unice 2: ");
List <int> mergedList = new List <int>();//initializam lista cu valorile unite ale celor doua liste de unicate
for (int i = 0; i < listaUnice1.Count; i++)
{
mergedList.Add(listaUnice1[i]);//populam lista unita cu valorile din prima lista de unicate
}
for (int i = 0; i < listaUnice2.Count; i++)
{
if (Metoda.Exista(listaUnice2[i], mergedList) == false) //daca valorile din lista a doua de unicate nu exista deja in lista unita
{
mergedList.Add(listaUnice2[i]); //le adaugam si pe acestea
}
}
Metoda.AfisareList(mergedList, " Merged list elements are: ");
}
public static void Exercitiul16()
{
Console.WriteLine(" 16. Algorithm to check if a number is Prime or not?");
//pentru a afla daca un nr este prim, acestuia ii trebuie verificata divizibilitatea cu toate nr prime mai mici decat el
Console.WriteLine(" Enter the number to check!");
Console.WriteLine(" (Please, choose a number < 10.000 if you want the result today :) )");
int numar = Convert.ToInt32(Console.ReadLine()); //preluare valoare utilizator in var. numar
int[] arrNumere = new int[numar]; //array-ul arrNumere creat prin
arrNumere = Metoda.GenIntArray2(numar); //apelarea functiei 'GenIntArray' din clasa 'Metoda'
List <int> lstDivizibile = new List <int>(); //initializare lista lstDivizibile
List <int> lstPrime = new List <int>(); //initializare lista lstPrime
for (int x = 0; x <= arrNumere.Length - 1; x++) //se creeaza o lista a divizibililor in vederea aflarii nr prime < nr verificat
{
for (int y = 0; y <= arrNumere.Length - 1; y++)
{
if (arrNumere[x] % arrNumere[y] == 0 && arrNumere[y] != 1 && arrNumere[x] != arrNumere[y])
{
lstDivizibile.Add(arrNumere[x]);
}
}
}
for (int x = 0; x <= arrNumere.Length - 1; x++)//se inloc val divizibililor din array, cu val. 0
{
for (int y = 0; y <= lstDivizibile.Count - 1; y++)
{
if (arrNumere[x] == lstDivizibile[y])
{
arrNumere[x] = 0;
}
}
}
for (int x = 0; x <= arrNumere.Length - 1; x++)//se creeaza lista nr prime
{
if (arrNumere[x] != 0)
{
lstPrime.Add(arrNumere[x]);
}
}
int counter = 0;
for (int x = 0; x <= lstPrime.Count - 1; x++)
{
if (numar % lstPrime[x] == 0 && lstPrime[x] != 1 && numar != lstPrime[x])
{
counter++;
Console.WriteLine(" Number {0} isn't prime because it's divisible by {1}.", numar.ToString(), lstPrime[x].ToString());
}
}
if (counter == 0)
{
Console.WriteLine(" Number {0} is prime!", numar.ToString());
}
//Metoda.AfisareList(lstPrime);
}
public static void Exercitiul6()
{
Console.WriteLine(" Ex.6. How to find sum of digits of a number using Recursion?");
int numar = Metoda.PrelParamInt();
int sumaCifre = Metoda.SumaCifreRecursiv(numar);
Console.WriteLine(" The number you entered is {0} and it's digits sum is: {1}", numar.ToString(), sumaCifre.ToString());
}
public static void Exercitiul19()
{
Console.WriteLine(" 19. How to rotate an array by a given pivot ?");
int lungime, valMax;
Metoda.PrelParamInt(out lungime, out valMax);
int[] arrInitial = new int[lungime];
arrInitial = Metoda.GenIntArray(lungime, valMax);
Metoda.AfisareArr(arrInitial);
Console.WriteLine(" Enter a value with the role of 'pivot':");
int pivot = Convert.ToInt32(Console.ReadLine());
int x = 0;
for (int i = 0; i < arrInitial.Length; i++)
{
if (pivot == arrInitial[i])
{
x = i;
}
}
Console.WriteLine(" The index of {0} is {1}.", pivot.ToString(), x.ToString());
List <int> lstRotit = new List <int> {
};
int j = 0;
int k = 0;
while (j < arrInitial.Length - x)
{
lstRotit.Add(arrInitial[j + x]);
j++;
}
for (j = arrInitial.Length - x; j < arrInitial.Length; j++)
{
while (k < x)
{
lstRotit.Add(arrInitial[k]);
k++;
}
}
//Metoda.AfisareList(lstRotit);
int[] arrRotit = new int[arrInitial.Length];
lstRotit.CopyTo(arrRotit, 0);
Metoda.AfisareArr(arrRotit);
}
public static void Exercitiul20()
{
Console.WriteLine(" 20. Sorting an Array using Selection Sort");
int lungime, valMax;
Metoda.PrelParamInt(out lungime, out valMax);
int[] arrNesortat = new int[lungime];
arrNesortat = Metoda.GenIntArray(lungime, valMax);
Metoda.AfisareArr(arrNesortat);
Metoda.SortareIntArray(arrNesortat);
Metoda.AfisareArr(arrNesortat);
}
public static void Exercitiul1()
{
Console.WriteLine(" Ex.1. Given an array of ints, write a C# method to total all the values that are even numbers.");
int lungArr, valArr;
Metoda.PrelParamInt(out lungArr, out valArr);
int[] newArr = new int[lungArr];
newArr = Metoda.GenIntArray(lungArr, valArr);
Metoda.AfisareArr(newArr);
Console.WriteLine("\n");
Console.WriteLine(" The sum of the EVEN numbers is: {0}", Metoda.SumaNrPareArr(newArr).ToString());
}
public static int CalculeazaArmstrong(List <int> lstCifre)
{
int x = 0;
int suma = 0;
for (int i = 0; i < lstCifre.Count; i++)
{
x = Metoda.CalculeazaPutere(lstCifre[i], lstCifre.Count);
Console.WriteLine(" cifra: {0} -- puterea: {1} -- valoarea: {2}", lstCifre[i].ToString(), lstCifre.Count.ToString(), x.ToString());
suma = suma + x;
}
Console.WriteLine("\n");
Console.WriteLine(" The sum of numbers above is: {0}", suma.ToString());
Console.WriteLine("\n");
return(suma);
}
public static void Exercitiul4()
{
Console.WriteLine(" Ex.4. Algorithm to find if Array contains duplicates?");
int lungArr, valArr;
Metoda.PrelParamInt(out lungArr, out valArr);
int[] newArr = new int [lungArr];
newArr = Metoda.GenIntArray(lungArr, valArr);
Metoda.AfisareArr(newArr);
List <int> lstUnicate = new List <int>();
lstUnicate = Metoda.EliminaDuplicate(newArr);
}
public static void Exercitiul13()
{
Console.WriteLine(" 13. Write a function to remove duplicate characters from String?");
Console.WriteLine(" Enter a few repetitive letters:");
string litere = Console.ReadLine();
string[] arrLitere = new string[litere.Length];
arrLitere = Metoda.GenStrArray(litere);
Metoda.AfisareArr(arrLitere);
List <string> lstUnice = new List <string>();
lstUnice = Metoda.EliminaDuplicate(arrLitere);
Metoda.AfisareList(lstUnice);
}
public static void Exercitiul3()
{
Console.WriteLine(" Ex.3. How to calculate factorial using recursion in C# + iterative + time difference.");
int numar = Metoda.PrelParamInt();
int[] factArr = new int[numar + 1];
factArr = Metoda.GenIntArray(numar);//.CopyTo(factArr,0);
Metoda.AfisareArr(factArr);
int x = Metoda.FactorialIterativ(factArr);
int y = Metoda.FactorialRecursiv(numar);
Console.WriteLine("\n");
Console.WriteLine(" Iterative: !{0} = {1}", numar.ToString(), x.ToString());
Console.WriteLine(" Recursive: !{0} = {1}", numar.ToString(), y.ToString());
}
public static void Exercitiul5()
{
Console.WriteLine(" Ex.5. How to remove duplicates from a sorted linked list?");
int lungime, valMax;
Metoda.PrelParamInt(out lungime, out valMax);
int[] arrayNou = new int[lungime];
arrayNou = Metoda.GenIntArray(lungime, valMax);
List <int> listaUnice = new List <int>();
listaUnice = Metoda.EliminaDuplicate(arrayNou);
Console.Write(" All the elements of the initial list...");
Metoda.AfisareArr(arrayNou);
Metoda.AfisareList(listaUnice, " Unique elements of the list...");
}
public static void Exercitiul7()
{
Console.WriteLine(" Ex.7. Given an unsorted array which has a number in the majority");
Console.WriteLine(" (a number appears more than 50% in the array), find that number?");
int lungime, valMax;
Metoda.PrelParamInt(out lungime, out valMax);
int[] arr = new int[lungime];
arr = Metoda.GenIntArray(lungime, valMax);
List <int> lstUnice = new List <int>();
for (int x = 0; x < arr.Length; x++)
{
int count = 0;
if (Metoda.Exista(arr[x], lstUnice) == true)//(lstUnice.Contains(newArr[x]))
{
continue;
}
lstUnice.Add(arr[x]);
for (int y = 0; y < arr.Length; y++)
{
if (arr[x] == arr[y])
{
count++;
}
}
if (count == 1)
{
Console.WriteLine(" Item {0} is unique.", arr[x].ToString());
}
if (count != 1)
{
Console.WriteLine(" Item {0} appears {1} times.", arr[x], count.ToString());
}
if (count > arr.Length / 2)
{
Console.WriteLine(" Item {0} is in majority!", arr[x]);
}
}
}
public static void Exercitiul17()
{
Console.WriteLine(" Ex.17. Algorithm to check if a number is Palindrome?");
Console.WriteLine(" Enter a number to check for 'palindrome' property: ");
int numar = Convert.ToInt32(Console.ReadLine());
List <int> listaCifre = new List <int>();
listaCifre = Metoda.GenIntListaCifre(numar);
Metoda.AfisareList(listaCifre, " Digits list is: ");
List <int> listaPeDos = new List <int>();
for (int i = 0; i < listaCifre.Count; i++)
{
listaPeDos.Add(listaCifre[listaCifre.Count - 1 - i]);
}
Metoda.AfisareList(listaPeDos, " Reversed digits list is: ");
int counter = 0;
for (int j = 0; j < listaCifre.Count; j++)
{
if (listaCifre[j] == listaPeDos[j])
{
counter++;
}
if (listaCifre[j] != listaPeDos[j])
{
counter--;
}
}
if (listaCifre.Count == counter)
{
Console.WriteLine(" Number {0} is a palindrome!", numar.ToString());
}
if (listaCifre.Count != counter)
{
Console.WriteLine(" Number {0} is NOT a palindrome!", numar.ToString());
}
}
public static void Exercitiul10()
{
Console.WriteLine(" Ex.10. Write a Program which checks if two Strings are Anagram or not?");
Console.WriteLine(" Enter the first few letters: ");
string firstString = Console.ReadLine();
Console.WriteLine(" Enter the second string:");
string secondString = Console.ReadLine();
string[] arrFirst = new string[firstString.Length];
arrFirst = Metoda.GenStrArray(firstString);
string[] arrSecond = new string[secondString.Length];
arrSecond = Metoda.GenStrArray(secondString);
Array.Sort(arrFirst);
Array.Sort(arrSecond);
int counter = 0;
for (int i = 0; i < arrFirst.Length; i++)
{
if (arrFirst[i] != arrSecond[i])
{
counter--;
}
if (arrFirst[i] == arrSecond[i])
{
counter++;
}
}
if (counter == arrFirst.Length && counter == arrSecond.Length)
{
Console.WriteLine(" The two strings are ANAGRAM!");
}
if (counter != arrFirst.Length)
{
Console.WriteLine(" The two strings are NOT anagram!");
}
}
public static void Exercitiul2()
{
Console.WriteLine(" Ex.2. How to find all pairs of elements in an integer array, ");
Console.WriteLine(" whose sum is equal to a given number?");
int numar = Metoda.PrelParamInt();
int[] termeniAddArr = new int[numar + 1];
//termeniAddArr = Metoda.GenIntArray(numar);//array ce contine toate nr de la 0 la nr introdus de utilizator
termeniAddArr = Metoda.GenIntArray(numar, numar);//array cu continut aleatoriu, functie de nr introdus de utilizator
List <int> lstDupl = new List <int>();
Metoda.AfisareArr(termeniAddArr);
for (int x = 0; x < termeniAddArr.Length; x++) //prima valoare din array, apoi a doua, ulterior a treia...
{
for (int y = 0; y < termeniAddArr.Length; y++) //comparata pe rand cu fiecare din valorile array-ului
{
if (Metoda.Exista(termeniAddArr[x], lstDupl) == true) //la prima rulare a buclei, aici e gol si trece peste
{ //incepand cu a doua, verifica daca exista in lista si sare la urmatoarea valoare
continue;
}
else
{
if (numar == termeniAddArr[x] + termeniAddArr[y]) //daca indeplineste conditia
{
lstDupl.Add(termeniAddArr[x]); //sunt ambele adaugate in lista
lstDupl.Add(termeniAddArr[y]);
Console.WriteLine("\n");
Console.Write(" {0} = {1} + {2}", numar.ToString(), termeniAddArr[x].ToString(), termeniAddArr[y].ToString());
}
}
}
}
}
public static void Exercitiul15()
{
Console.WriteLine(" 15. C# program to check if a number is Armstrong number or not?");
Console.WriteLine(" Enter a number to check for Armstrong property: ");
int numar = Convert.ToInt32(Console.ReadLine());
List <int> lstCifre = new List <int>();
lstCifre = Metoda.GenIntListaCifre(numar);
Metoda.AfisareList(lstCifre, " Digits list is: ");
int nrArm = Metoda.CalculeazaArmstrong(lstCifre);
if (numar == nrArm)
{
Console.WriteLine(" The number you entered is an Armstrong number!");
}
if (numar != nrArm)
{
Console.WriteLine(" The number you entered is NOT an Armstrong number!");
}
}
