Write a program to find Fibonacci series of n numbers in C++.

        In mathematics, the Fibonacci numbers or Fibonacci sequence are the numbers in the following integer sequence:

01, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144.....

The Fibonacci spiral: an approximation of the golden spiral created by drawing circular arcs connecting the opposite corners of squares in the Fibonacci tiling; this one uses squares of sizes 1, 1, 2, 3, 5, 8, 13, 21, and 34.

By definition, the first two numbers in the Fibonacci sequence are either 1 and 1, or 0 and 1, depending on the chosen starting point of the sequence, and each subsequent number is the sum of the previous two. 

Information source: wikipedia.org

Program:->

Output

#include <iostream>
using namespace std;
int fibo(int);
int main() {
int n,i;
cout<<"Enter the total elements in the series: ";
cin>>n;
cout<<"The Fibonacci series is: \n";
fibo(n);
return(0);
}
int fibo(int x) {
int f=-1,s=1,n;
for (int i = 0; i < x; ++i) {
n=f+s;
f=s;
s=n;
cout<<n<<"\n";
}
return(0);
}

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Write a program to find factorial of a number in C++.

     In mathematics, the factorial of a non-negative integer n, denoted by n!, is the product of all positive integers less than or equal to n. For example,

5! = 5  *  4  *  3  *  2  * 1 = 120.

The value of 0! is 1, according to the convention for an empty product.

The factorial operation is encountered in many areas of mathematics, notably in combinatorics, algebra, and mathematical analysis. Its most basic occurrence is the fact that there are n! ways to arrange n distinct objects into a sequence (i.e., permutations of the set of objects). This fact was known at least as early as the 12th century, to Indian scholars. Fabian Stedman in 1677 described factorials as applied to change ringing.

Information source: wikipedia.org

Program:->

Output

#include <iostream>
using namespace std;
int main() {
int x,f=1;
cout<<"Enter a number: ";
cin>>x;
for (int i = 1; i <= x; ++i) {
f=f*i;
}
cout<<"Factorial: "<<f<<"\n";
return(0);
}

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Write a program to insert info\elements in the Linked List.

Output

#include <iostream>
using namespace std;
struct node {
int info;
node* link;
}*start,*nNode;
node * createNew() {
nNode = new node;
cout<<"Enter info for node: ";
cin>>nNode->info;
return (nNode);
}
node display(node* temp) {
while(temp!=NULL) {
cout<<temp->info<<"\n";
temp=temp->link;
}
}
int main() {
int n=2,s,af;
start=NULL;
node* tempPtr;
cout<<"Press 1 to enter new node: ";
cin>>n;
while(n==1) {
cout<<"Where you want to insert node: \n1- In begining\t\t2- In between\t\t3- At end\n";
cin>>s;
switch(s) {
case 1:
if(start==NULL) {
start=createNew();
start->link=NULL;
} else {
nNode=createNew();
nNode->link=start;
start=nNode;
}
break;
case 2:
cout<<"\nInfo in linked list: \n";
display(start);
cout<<"After which info you want new element: ";
cin>>af;
tempPtr=start;
while(tempPtr!=NULL && tempPtr->info!=af) {
tempPtr=tempPtr->link;
}
if (tempPtr==NULL) {
cout<<"Entered info not found.\n";
} else {
nNode=createNew();
nNode->link=tempPtr->link;
tempPtr->link=nNode;
}
break;
case 3:
tempPtr=start;
while(tempPtr->link!=NULL && tempPtr!=NULL) {
tempPtr=tempPtr->link;
}
nNode=createNew();
tempPtr->link=nNode;
nNode->link=NULL;
break;
default:
cout<<"\n**************Error**************\n";
}
cout<<"Press 1 to enter new node or other no. to exit: ";
cin>>n;
}
tempPtr=start;
cout<<"\nInfo in linked list:\n";
display(start);
return (0);
}

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Write a program to search a node of the Linked List.

Output

#include <iostream>
using namespace std;
struct node {
int info;
node* link;
}*start,*nNode;
node * createNew(int in) {
nNode = new node;
nNode->info=in;
return (nNode);
}
node display(node* temp) {
while(temp!=NULL) {
cout<<temp->info<<"  ";
temp=temp->link;
}
cout<<"\n";
}
node * search(node* tempPtr,int item) {
while(tempPtr!=NULL && tempPtr->info!=item) {
tempPtr=tempPtr->link;
}
return (tempPtr);
}
int main()
{
int n=2,s,item;
int a[8]={7,9,8,5,4,6,2,1};
start=NULL;
node* tempPtr;
for (int i = 0; i < 8; ++i)
{
if(start==NULL) {
start=createNew(a[i]);
start->link=NULL;
} else {
nNode=createNew(a[i]);
nNode->link=start;
start=nNode;
}
}
cout<<"Elements of linked list: \n";
display(start);
cout<<"Enter element you want to search: ";
cin>>item;
tempPtr=search(start,item);
if (tempPtr!=NULL && tempPtr->info==item) {
cout<<"Item found in list.\n";
} else {
cout<<"Item doesn't exists in list.\n";
}
return(0);
}

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Write a program to solve a quadratic equation.

Output

#include <iostream>
#include <math.h>
using namespace std;
int main()
{
int a,b,c,d=0,x;
cout<<"Enter a,b & c:";
cin>>a>>b>>c;
d=(b*b)-4*a*c;
cout<<"Result:\n";
if(d<0) {
cout<<"d<0"<<endl;
cout<<(-b-sqrt(d))/2*a<<endl;
cout<<(-b+sqrt(d))/2*a<<endl;
} else if(d==0) {
cout<<"D=0"<<endl;
cout<<-b/2*a<<endl;;
} else {
cout<<"D>0"<<endl;
cout<<"Imaginary number: "<<endl;
}
}

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Write a program to sort elements of an array using Merge Sort.

Output

#include <iostream>
using namespace std;
int mergeSort(int a[],int beg,int end);
int merge(int a[],int beg,int mid,int end);
int main()
{
int n,a[100];
cout<<"Enter no. of values: ";
cin>>n;
cout<<"Enter "<<n<<" values: ";
for(int x=0;x<n;x++) {
cin>>a[x];
}
mergeSort(a,0,n-1);
cout<<"Array after Sorting using Merge Sort:\n";
for(int x=0;x<n;x++) {
cout<<a[x]<<"\n";
}
return(0);
}
int mergeSort(int a[],int beg,int end)
{
if(end <= beg) {
return(0);
}
int mid=(beg+end)/2;
mergeSort(a,beg,mid);
mergeSort(a,mid+1,end);
merge(a,beg,mid,end);
}
int merge(int a[],int beg,int mid,int end)
{
int h=beg,i=beg,j=mid+1;
int b[100];
while(h<=mid && j<=end) {
if(a[h]<=a[j]) {
b[i]=a[h];
i++;
h++;
} else {
b[i]=a[j];
i++;
j++;
}
}
if(h>mid) {
for(int k=j;k<=end;k++) {
b[i]=a[k];
i++;
}
} else {
for(int k=h;k<=mid;k++) {
b[i]=a[k];
i++;
}
}
for(int k=beg;k<=end;k++) {
a[k]=b[k];
}
}

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Write a program to search an element of an array using binary search.

Output

#include <iostream.h>
using namespace std;
int a[100];
int main()
{
int n,item,loc;
int binary(int beg,int end,int item);
cout<<"Enter no. of elements: ";
cin>>n;
cout<<"Enter "<<n<<" elements in Sorted Order: ";
for(int i=0;i<n;i++) {
cin>>a[i];
}
cout<<"Enter item you want to search: ";
cin>>item;
loc=binary(0,n,item);
if(a[loc]==item) {
cout<<"\nData is Found at Location: "<<loc<<"\n";
} else {
cout<<"Data is Not Found";
}
}
int binary(int beg,int end,int item)
{
int mid=(beg+end)/2;
if (end < beg) {
    return -1;
}
if (a[mid]==item) {
return(mid);
} else if(a[mid]<item) {
binary(mid+1,end,item);
} else {
binary(beg,mid-1,item);
}
}

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Write a program to search a value from an array in C++.

     In computer science, a search data structure is any data structure that allows the efficient retrieval of specific items from a set of items, such as a specific record from a database.

The simplest, most general, and least efficient search structure is merely an unordered sequential list of all the items. Locating the desired item in such a list, by the linear search method, inevitably requires a number of operations proportional to the number n of items, in the worst case as well as in the average case. Useful search data structures allow faster retrieval; however, they are limited to queries of some specific kind. Moreover, since the cost of building such structures is at least proportional to n, they only pay off if several queries are to be performed on the same database (or on a database that changes little between queries).

Information source: wikipedia.org

Program:->

Output

#include <iostream>
using namespace std;
int main()
{
int loc,n,data,a[100];
cout<<"Enter no. of values: ";
cin>>n;
cout<<"Enter "<<n<<" values: ";
for(int x=0;x<n;x++) {
cin>>a[x];
}
cout<<"Entered array is: "<<"\n";
for(int x=0;x<n;x++) {
cout<<a[x]<<"  ";
}
cout<<"\nEnter data to search: ";
cin>>data;
for(int x=0;x<n;x++) {
if(data==a[x]) {
cout<<"Location is: "<<x<<"\n";
loc=x;
break;
}
loc=x;
}
if(data!=a[loc]) {
cout<<"Element not found\n";
}
return(0);
}

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Write a program to sort elements of an array using Insertion Sort.

Output

#include <iostream>

using namespace std;
int insertionSort(int a[],int n);
int main()
{
int n,data,a[100];
cout<<"Enter no. of values: ";
cin>>n;
cout<<"Enter "<<n<<" values: ";
for(int x=0;x<n;x++) {
cin>>a[x];
}
insertionSort(a,n);
cout<<"Array after Sorting using Insertion Sort: \n";
for(int x=0;x<n;x++) {
cout<<a[x]<<"\n";
}
return(0);
}
int insertionSort(int a[],int n)
{
int pivot,temp;
for(int startPos=1;startPos<n;startPos++) {
pivot=startPos;
while(pivot >= 1 && a[pivot] < a[pivot-1]) {
temp=a[pivot];
a[pivot]=a[pivot-1];
a[pivot-1]=temp;
pivot--;
}
}
}

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Write a program to find first n prime numbers.

Output

#include <iostream.h>

using namespace std;
int main()
{
   int n, i = 3, count, c;
   cout<<"Enter the number of prime numbers required: ";
   cin>>n;
   if ( n >= 1 ) {
      cout<<"First "<<n<<" prime numbers are:\n";
      cout<<"2\n";
   }
   count = 2 ;
   while (count <= n) {
      for ( c = 2 ; c <= i - 1 ; c++ ) {
         if ( i%c == 0 )
            break;
      }
      if ( c == i ) {
         cout<<i<<"\n";
         count++;
      }
      i++;
   }
   return 0;
}

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Write a program to find a largest number from n numbers.

Output

#include <iostream>

using namespace std;
int main()
{
int z,n,a[100];
cout<<"Enter no. of values: ";
cin>>n;
cout<<"Enter "<<n<<" values: ";
for(int x=0;x<n;x++)
{
cin>>a[x];
}
z=a[0];
for(int x=1;x<n;x++)
{
if(z<a[x]) {
z=a[x];
}
}
cout<<"Largest: "<<z<<"\n";
}

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Write a program to calculate sum of the elements of an 2D array.

#include<iostream>
using namespace std;
int main()
{
int a[100][100];
int r,c;
cout<<"Enter no. of rows & columns: ";
cin>>r>>c;;
cout<<"Enter "<<r*c<<" values : ";
for(int i=0;i<r;i++) {
for(int j=0;j<c;j++) {
cin>>a[i][j];
}
}
for(int i=0;i<r;i++) {
for(int j=0;j<c;j++) {
a[i][c]+=a[i][j];
}

}
for(int i=0;i<r;i++) {
for(int j=0;j<c+1;j++) {
a[r][j]+=a[i][j];
}

}
cout<<"SUM : "<<"\n";
for(int i=0;i<r+1;i++) {
for(int j=0;j<c+1;j++) {
cout<<a[i][j]<<" ";
}
cout<<"\n";
}
}

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Write a program to sort elements of an array using Quick Sort.

#include <iostream>

using namespace std;
int quickSort(int a[],int l,int r);
int main()
{
int n,data,a[100];
cout<<"Enter no. of values: ";
cin>>n;
cout<<"Enter "<<n<<" values : ";
for(int x=0;x<n;x++) {
cin>>a[x];
}
quickSort(a,0,n);
cout<<"Array after Sorting using Quick Sort: \n";
for(int x=0;x<n;x++) {
cout<<a[x]<<"\n";
}
return(0);
}
int quickSort(int a[],int l,int r)
{
int temp;
if(r-l<=1) {
return(0);
}
int y=l+1;
for(int g=l+1;g<r;g++) {
if(a[g]<=a[l]) {
temp=a[y];
a[y]=a[g];
a[g]=temp;
y++;
}
}
temp=a[y-1];
a[y-1]=a[l];
a[l]=temp;
quickSort(a,l,y-1);
quickSort(a,y,r);
}

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Write a program to sort elements of an array using Bubble Sort.

Bubble sort, sometimes referred to as sinking sort, is a simple sorting algorithm that repeatedly steps through the list to be sorted, compares each pair of adjacent items and swaps them if they are in the wrong order. 

The pass through the list is repeated until no swaps are needed, which indicates that the list is sorted. The algorithm, which is a comparison sort, is named for the way smaller elements "bubble" to the top of the list. Although the algorithm is simple, it is too slow and impractical for most problems even when compared to insertion sort. It can be practical if the input is usually in sorted order but may occasionally have some out-of-order elements nearly in position.

Performance:->

• Best case: O(n)
• Average case: О(n²)
• Worst case: О(n²)

Information source: wikipedia.org

Program:->

Output

#include <iostream>
using namespace std;
int bubble(int *ptr,int n);
int main()
{
int n,data,a[100];
int *ptr;
ptr=a;
cout<<"Enter no. of values: ";
cin>>n;
cout<<"Enter "<<n<<" values: ";
for(int x=0;x<n;x++) {
cin>>*(ptr+x);
}
bubble(ptr,n);
cout<<"Array after Sorting using BUBBLE Sort: \n";
for(int x=0;x<n;x++) {
cout<<*(ptr+x)<<"\n";
}
return(0);
}
int bubble(int *ptr,int n)
{
int x,temp;
for(int k=0;k<n;k++) {
x=0;
while(x<n-k-1) {
if(*(ptr+x)>*(ptr+x+1)) {
temp=*(ptr+x+1);
*(ptr+x+1)=*(ptr+x);
*(ptr+x)=temp;
}
x=x+1;
}
}
}

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Write a program to reverse the elements of an array.

An array type is a data type that is meant to describe a collection of elements (values or variables), each selected by one or more indices (identifying keys) that can be computed at run time by the program. Such a collection is usually called an array variable, array value, or simply array. By analogy with the mathematical concepts of vector and matrix, array types with one and two indices are often called vector type and matrix type, respectively.

In order to effectively implement variables of such types as array structures (with indexing done by pointer arithmetic), many languages restrict the indices to integer data types (or other types that can be interpreted as integers, such as bytes and enumerated types), and require that all elements have the same data type and storage size. Most of those languages also restrict each index to a finite interval of integers, that remains fixed throughout the lifetime of the array variable. In some compiled languages, in fact, the index ranges may have to be known at compile time.

Information source: wikipedia.org

Program:->

Output

#include <iostream.h>
using namespace std;
int main() {
   int arr[30], i, j, num, temp;

   cout<<"Enter no. of elements : ";
   cin>>num;
   cout<<"Enter "<<num<<" values : ";
   for (i = 0; i < num; i++) {
      cin>>arr[i];
   }
   j = num - 1;
   i = 0;  
   while (i < j) {
      temp = arr[i];
      arr[i] = arr[j];
      arr[j] = temp;
      i++;
      j--;
   }
   cout<<"\nResult after reversal : ";
   for (i = 0; i < num; i++) {
      cout<<arr[i]<<"   ";
   }
   return (0);
}

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