Array notes
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The document discusses arrays in C++. It defines an array as a collection of similar data types that share a common name and whose elements can be distinguished using indexes. It provides the syntax for declaring arrays and examples. It also describes different methods for initializing arrays and provides sample questions and solutions demonstrating how to read from, modify, and sort arrays in C++.
![By : Rakesh Kumar D.A.V. Centenary Public School
Array
Array is a collection of similar data types sharing a common name and one element can be distinguished using their
index.
Syntax to declare Array
datatype identifier[size];
Example
int x[10];
float f[20]
The size of array can not be variable, it is recommended as a integer constant values without any type of positive or
negative sign.
When an array is declared using it’s syntax. The compiler creates the defined number of blocks in continuation. Each
block is assigned a unique index number which start from 0(Zero).
Example
x[0] x[1] x[2] x[3] x[4]
10 20 30 40 50
Initialization Method
Declaration and
Method-I initialization simultaneouly
int x[5] = {10,20,30,40,50 };
Method –II Only when declaration + initialization simultaneously
takesh place
int x[] = { 10,20,30,40,50 };
Method –III
int x[5];
x[0] =10;
x[1]=20;
x[2]=30;
x[3]=40;
x[4]=50;
Method –IV
int x[5];
cin>>x[0]>>x[1]>>x[2]>>x[3]>>x[4];
Method V
int x[5];
For(i=0;I,5;i++)
cin>>x[i];
Some Sample Question and Their Solution
Write a program in C++ to read an array of integer of Write a program in C++ to read an array of integer
size 10 . Also display the same on the screen. of size 10 and give an increment of 20 to each element.
Also display this modified list on the screen
#include<iostream> #include<iostream>
#include<iomanip> #include<iomanip>
#include<conio.h> #include<conio.h>
using namespace std; using namespace std;
int main() int main()
{ {
int x[10],i; int x[10],i;
for(i=0;i<10;i++) // input phase
{ for(i=0;i<10;i++)
cout<<"Enter x["<<i<<"] element {
:"; cout<<"Enter x["<<i<<"] element
cin>>x[i]; :";
} cin>>x[i];
cout<<"n Entered array :"; }
8](https://image.slidesharecdn.com/arraynotes-111219120205-phpapp02/85/Array-notes-1-320.jpg)
![By : Rakesh Kumar D.A.V. Centenary Public School
for(i=0;i<10;i++) // processing phase
cout<<setw(6)<<x[i]; for(i=0;i<10;i++)
getch(); x[i] = x[i]+20;
return 0;
} cout<<"n Entered array :";
for(i=0;i<10;i++)
cout<<setw(6)<<x[i];
getch();
return 0;
}
Write a program in C++ to read an array of integer Write a program in C++ to read an array of integer
of size 10 and find out the sum of even element and of size 10 and swap it’s first element with the last half
the sum of odd element. Also display this entered of it’s element and display the result on the screen.
array and sums on the screen.
#include<iostream> #include<iostream>
#include<iomanip> #include<iomanip>
#include<conio.h> #include<conio.h>
using namespace std; using namespace std;
int main() int main()
{ {
int x[10],i,seven,sodd; int x[10],i,temp,j;
// input phase // input phase
for(i=0;i<10;i++) for(i=0;i<10;i++)
{ {
cout<<"Enter x["<<i<<"] element cout<<"Enter x["<<i<<"] element :";
:"; cin>>x[i];
cin>>x[i]; }
} // processing phase
// processing phase
seven=sodd=0; for(i=0,j=9;i<5;i++,j--)
for(i=0;i<10;i++) {
if(x[i]%2==0) temp = x[i];
seven +=x[i]; x[i] = x[j];
else x[j] = temp;
sodd += x[i]; }
// output phase // output phase
cout<<"n Entered array :"; cout<<"n Swaped array :";
for(i=0;i<10;i++) for(i=0;i<10;i++)
cout<<setw(6)<<x[i]; cout<<setw(6)<<x[i];
cout<<"n Sum of Even Element :"<<seven; getch();
cout<<"n Sum of Odd element :"<<sodd; return 0;
getch(); }
return 0;
}
Bubble Sort ( Ascending Order)
#include<iostream>
#include<iomanip>
#include<conio.h>
using namespace std;
// function to read an array from the keyboard
void input(int x[],int n)
{
for(int i=0;i<n;i++)
{
cout<<"Enter "<<i<<" element :";
cin>>x[i];
}
return;
}
8](https://image.slidesharecdn.com/arraynotes-111219120205-phpapp02/85/Array-notes-2-320.jpg)
![By : Rakesh Kumar D.A.V. Centenary Public School
// function to display an arry on the screen
void output(int x[],int n)
{
for(int i=0;i<n;i++)
cout<<setw(6)<<x[i];
return;
}
// function to sort an array using bubble sort method
void bubble_sort(int x[],int n)
{
int i,j,temp;
for(i=0;i<n-1;i++)
for(j=0;j<n-1-i;j++)
{
if(x[j]>x[j+1])
{
temp = x[j];
x[j] = x[j+1];
x[j+1] = temp;
}
}
return;
}
int main()
{
int x[10];
input(x,10);
bubble_sort(x,10);
cout<<"n Sorted Array :";
output(x,10);
getch();
return 0;
}
Selection Sort
#include<iostream>
#include<iomanip>
#include<conio.h>
using namespace std;
// function to read an array from the keyboard
void input(int x[],int n)
{
for(int i=0;i<n;i++)
{
cout<<"Enter "<<i<<" element :";
cin>>x[i];
}
return;
}
// function to display an arry on the screen
void output(int x[],int n)
{
for(int i=0;i<n;i++)
cout<<setw(6)<<x[i];
return;
}
// function to sort an array using selection sort
void selection_sort(int x[],int n)
{
int i,j,pos,low, temp;
for(i=0;i<n-1;i++)
{
pos = i;
8](https://image.slidesharecdn.com/arraynotes-111219120205-phpapp02/85/Array-notes-3-320.jpg)
![By : Rakesh Kumar D.A.V. Centenary Public School
low = x[i];
for(j=i+1;j<n-1;j++)
{
if(low>x[j])
{
low = x[j];
pos=j;
}
}
temp = x[i];
x[i] = x[pos];
x[pos] = temp;
}
}
int main()
{
int x[10];
input(x,10);
selection_sort(x,10);
cout<<"n Sorted Array :";
output(x,10);
getch();
return 0;
}
INSERTION SORT
#include<iostream>
#include<iomanip>
#include<conio.h>
using namespace std;
// function to read an array from the keyboard
void input(int x[],int n)
{
for(int i=0;i<n;i++)
{
cout<<"Enter "<<i<<" element :";
cin>>x[i];
}
return;
}
// function to display an arry on the screen
void output(int x[],int n)
{
for(int i=0;i<n;i++)
cout<<setw(6)<<x[i];
return;
}
// function to sort an array using insertion sort
void insertion_sort(int x[],int n)
{
int i,j,temp;
for(i=1;i<n;i++)
{
temp = x[i];
j = i-1 ;
while(temp<x[j] && j>=0)
{
x[j+1] = x[j];
j = j-1;
}
x[j+1]= temp;
}
8](https://image.slidesharecdn.com/arraynotes-111219120205-phpapp02/85/Array-notes-4-320.jpg)
![By : Rakesh Kumar D.A.V. Centenary Public School
return;
}
int main()
{
int x[10];
input(x,10);
insertion_sort(x,10);
cout<<"n Sorted Array :";
output(x,10);
getch();
return 0;
}
Contatenation
#include<iostream>
#include<iomanip>
#include<conio.h>
using namespace std;
// function to read an array from the keyboard
void input(int x[],int n)
{
for(int i=0;i<n;i++)
{
cout<<"Enter "<<i<<" element :";
cin>>x[i];
}
return;
}
// function to display an arry on the screen
void output(int x[],int n)
{
for(int i=0;i<n;i++)
cout<<setw(6)<<x[i];
return;
}
// search an element using binary search
void concate(int x[],int m,int y[],int n, int z[])
{
for(int i=0;i<m;i++)
z[i] = x[i];
for(int i=0;i<n;i++)
z[m+i] = y[i];
return;
}
int main()
{
int x[5],y[10],z[15];
cout<<"n ARRAY Xn";
input(x,5);
cout<<"n ARRAY Yn";
input(y,10);
concate(x,5,y,10,z);
system("cls");
cout<<"n Array A : ";
output(x,5);
cout<<"n Array B : ";
output(y,10);
cout<<"n Concatenated Array : ";
output(z,15);
getch();
return 0;}
8](https://image.slidesharecdn.com/arraynotes-111219120205-phpapp02/85/Array-notes-5-320.jpg)
![By : Rakesh Kumar D.A.V. Centenary Public School
Merging
#include<iostream>
#include<iomanip>
#include<conio.h>
using namespace std;
// function to read an array from the keyboard
void input(int x[],int n)
{
for(int i=0;i<n;i++)
{
cout<<"Enter "<<i<<" element :";
cin>>x[i];
}
return;
}
// function to display an arry on the screen
void output(int x[],int n)
{
for(int i=0;i<n;i++)
cout<<setw(6)<<x[i];
return;
}
// merge two array to produce third array
void concate(int a[],int m,int b[],int n, int c[])
{
int i,j,k;
i=j=k=0;
while(i<m && j<n )
if(a[i]<b[j])
c[k++] = a[i++];
else
c[k++] = b[j++];
while(i<m)
c[k++]= a[i++];
while(j<n)
c[k++]= b[j++];
return;
}
int main()
{
int x[5],y[10],z[15];
cout<<"n ARRAY Xn";
input(x,5);
cout<<"n ARRAY Yn";
input(y,10);
concate(x,5,y,10,z);
system("cls");
cout<<"n Array A : ";
output(x,5);
cout<<"n Array B : ";
output(y,10);
cout<<"n Merged Array : ";
output(z,15);
getch();
return 0;}
Linear Search
#include<iostream>
#include<iomanip>
#include<conio.h>
using namespace std;
8](https://image.slidesharecdn.com/arraynotes-111219120205-phpapp02/85/Array-notes-6-320.jpg)
![By : Rakesh Kumar D.A.V. Centenary Public School
// function to read an array from the keyboard
void input(int x[],int n)
{
for(int i=0;i<n;i++)
{
cout<<"Enter "<<i<<" element :";
cin>>x[i];
}
return;
}
// function to display an arry on the screen
void output(int x[],int n)
{
for(int i=0;i<n;i++)
cout<<setw(6)<<x[i];
return;
}
// search an element using linear search
int linear_search(int x[],int n,int data)
{
int i,found =0;
for(i=0;i<n;i++)
{
if(x[i]==data)
found =1;
}
return found;
}
int main()
{
int x[10],data;
input(x,10);
cout<<"n Enter element to search :";
cin>>data;
int res = linear_search(x,10,data);
cout<<"n Entered Array :";
output(x,10);
if(res ==1)
cout<<"n Given data available in given array ";
else
cout<<"n Given data not available in given array ";
getch();
return 0;
}
Binary Search
#include<iostream>
#include<iomanip>
#include<conio.h>
using namespace std;
// function to read an array from the keyboard
void input(int x[],int n)
{
for(int i=0;i<n;i++)
{
cout<<"Enter "<<i<<" element :";
cin>>x[i];
}
return;
}
// function to display an arry on the screen
void output(int x[],int n)
{
8](https://image.slidesharecdn.com/arraynotes-111219120205-phpapp02/85/Array-notes-7-320.jpg)
![By : Rakesh Kumar D.A.V. Centenary Public School
for(int i=0;i<n;i++)
cout<<setw(6)<<x[i];
return;
}
// search an element using binary search
int binary_search(int x[],int n,int data)
{
int first,last,mid ,found =0;
first =0;
last = n-1;
while(first<=last && found ==0)
{
mid = (first+last)/2;
if(x[mid] == data)
found =1;
else
if(x[mid]>data)
last = mid-1;
else
first = mid+1;
}
return found;
}
int main()
{
int x[10],data;
input(x,10);
cout<<"n Enter element to search :";
cin>>data;
int res = binary_search(x,10,data);
cout<<"n Entered Array :";
output(x,10);
if(res ==1)
cout<<"n Given data available in given array ";
else
cout<<"n Given data not available in given array ";
getch();
return 0;
}
8](https://image.slidesharecdn.com/arraynotes-111219120205-phpapp02/85/Array-notes-8-320.jpg)
Array notes
- 1. By : Rakesh Kumar D.A.V. Centenary Public School Array Array is a collection of similar data types sharing a common name and one element can be distinguished using their index. Syntax to declare Array datatype identifier[size]; Example int x[10]; float f[20] The size of array can not be variable, it is recommended as a integer constant values without any type of positive or negative sign. When an array is declared using it’s syntax. The compiler creates the defined number of blocks in continuation. Each block is assigned a unique index number which start from 0(Zero). Example x[0] x[1] x[2] x[3] x[4] 10 20 30 40 50 Initialization Method Declaration and Method-I initialization simultaneouly int x[5] = {10,20,30,40,50 }; Method –II Only when declaration + initialization simultaneously takesh place int x[] = { 10,20,30,40,50 }; Method –III int x[5]; x[0] =10; x[1]=20; x[2]=30; x[3]=40; x[4]=50; Method –IV int x[5]; cin>>x[0]>>x[1]>>x[2]>>x[3]>>x[4]; Method V int x[5]; For(i=0;I,5;i++) cin>>x[i]; Some Sample Question and Their Solution Write a program in C++ to read an array of integer of Write a program in C++ to read an array of integer size 10 . Also display the same on the screen. of size 10 and give an increment of 20 to each element. Also display this modified list on the screen #include<iostream> #include<iostream> #include<iomanip> #include<iomanip> #include<conio.h> #include<conio.h> using namespace std; using namespace std; int main() int main() { { int x[10],i; int x[10],i; for(i=0;i<10;i++) // input phase { for(i=0;i<10;i++) cout<<"Enter x["<<i<<"] element { :"; cout<<"Enter x["<<i<<"] element cin>>x[i]; :"; } cin>>x[i]; cout<<"n Entered array :"; } 8
- 2. By : Rakesh Kumar D.A.V. Centenary Public School for(i=0;i<10;i++) // processing phase cout<<setw(6)<<x[i]; for(i=0;i<10;i++) getch(); x[i] = x[i]+20; return 0; } cout<<"n Entered array :"; for(i=0;i<10;i++) cout<<setw(6)<<x[i]; getch(); return 0; } Write a program in C++ to read an array of integer Write a program in C++ to read an array of integer of size 10 and find out the sum of even element and of size 10 and swap it’s first element with the last half the sum of odd element. Also display this entered of it’s element and display the result on the screen. array and sums on the screen. #include<iostream> #include<iostream> #include<iomanip> #include<iomanip> #include<conio.h> #include<conio.h> using namespace std; using namespace std; int main() int main() { { int x[10],i,seven,sodd; int x[10],i,temp,j; // input phase // input phase for(i=0;i<10;i++) for(i=0;i<10;i++) { { cout<<"Enter x["<<i<<"] element cout<<"Enter x["<<i<<"] element :"; :"; cin>>x[i]; cin>>x[i]; } } // processing phase // processing phase seven=sodd=0; for(i=0,j=9;i<5;i++,j--) for(i=0;i<10;i++) { if(x[i]%2==0) temp = x[i]; seven +=x[i]; x[i] = x[j]; else x[j] = temp; sodd += x[i]; } // output phase // output phase cout<<"n Entered array :"; cout<<"n Swaped array :"; for(i=0;i<10;i++) for(i=0;i<10;i++) cout<<setw(6)<<x[i]; cout<<setw(6)<<x[i]; cout<<"n Sum of Even Element :"<<seven; getch(); cout<<"n Sum of Odd element :"<<sodd; return 0; getch(); } return 0; } Bubble Sort ( Ascending Order) #include<iostream> #include<iomanip> #include<conio.h> using namespace std; // function to read an array from the keyboard void input(int x[],int n) { for(int i=0;i<n;i++) { cout<<"Enter "<<i<<" element :"; cin>>x[i]; } return; } 8
- 3. By : Rakesh Kumar D.A.V. Centenary Public School // function to display an arry on the screen void output(int x[],int n) { for(int i=0;i<n;i++) cout<<setw(6)<<x[i]; return; } // function to sort an array using bubble sort method void bubble_sort(int x[],int n) { int i,j,temp; for(i=0;i<n-1;i++) for(j=0;j<n-1-i;j++) { if(x[j]>x[j+1]) { temp = x[j]; x[j] = x[j+1]; x[j+1] = temp; } } return; } int main() { int x[10]; input(x,10); bubble_sort(x,10); cout<<"n Sorted Array :"; output(x,10); getch(); return 0; } Selection Sort #include<iostream> #include<iomanip> #include<conio.h> using namespace std; // function to read an array from the keyboard void input(int x[],int n) { for(int i=0;i<n;i++) { cout<<"Enter "<<i<<" element :"; cin>>x[i]; } return; } // function to display an arry on the screen void output(int x[],int n) { for(int i=0;i<n;i++) cout<<setw(6)<<x[i]; return; } // function to sort an array using selection sort void selection_sort(int x[],int n) { int i,j,pos,low, temp; for(i=0;i<n-1;i++) { pos = i; 8
- 4. By : Rakesh Kumar D.A.V. Centenary Public School low = x[i]; for(j=i+1;j<n-1;j++) { if(low>x[j]) { low = x[j]; pos=j; } } temp = x[i]; x[i] = x[pos]; x[pos] = temp; } } int main() { int x[10]; input(x,10); selection_sort(x,10); cout<<"n Sorted Array :"; output(x,10); getch(); return 0; } INSERTION SORT #include<iostream> #include<iomanip> #include<conio.h> using namespace std; // function to read an array from the keyboard void input(int x[],int n) { for(int i=0;i<n;i++) { cout<<"Enter "<<i<<" element :"; cin>>x[i]; } return; } // function to display an arry on the screen void output(int x[],int n) { for(int i=0;i<n;i++) cout<<setw(6)<<x[i]; return; } // function to sort an array using insertion sort void insertion_sort(int x[],int n) { int i,j,temp; for(i=1;i<n;i++) { temp = x[i]; j = i-1 ; while(temp<x[j] && j>=0) { x[j+1] = x[j]; j = j-1; } x[j+1]= temp; } 8
- 5. By : Rakesh Kumar D.A.V. Centenary Public School return; } int main() { int x[10]; input(x,10); insertion_sort(x,10); cout<<"n Sorted Array :"; output(x,10); getch(); return 0; } Contatenation #include<iostream> #include<iomanip> #include<conio.h> using namespace std; // function to read an array from the keyboard void input(int x[],int n) { for(int i=0;i<n;i++) { cout<<"Enter "<<i<<" element :"; cin>>x[i]; } return; } // function to display an arry on the screen void output(int x[],int n) { for(int i=0;i<n;i++) cout<<setw(6)<<x[i]; return; } // search an element using binary search void concate(int x[],int m,int y[],int n, int z[]) { for(int i=0;i<m;i++) z[i] = x[i]; for(int i=0;i<n;i++) z[m+i] = y[i]; return; } int main() { int x[5],y[10],z[15]; cout<<"n ARRAY Xn"; input(x,5); cout<<"n ARRAY Yn"; input(y,10); concate(x,5,y,10,z); system("cls"); cout<<"n Array A : "; output(x,5); cout<<"n Array B : "; output(y,10); cout<<"n Concatenated Array : "; output(z,15); getch(); return 0;} 8
- 6. By : Rakesh Kumar D.A.V. Centenary Public School Merging #include<iostream> #include<iomanip> #include<conio.h> using namespace std; // function to read an array from the keyboard void input(int x[],int n) { for(int i=0;i<n;i++) { cout<<"Enter "<<i<<" element :"; cin>>x[i]; } return; } // function to display an arry on the screen void output(int x[],int n) { for(int i=0;i<n;i++) cout<<setw(6)<<x[i]; return; } // merge two array to produce third array void concate(int a[],int m,int b[],int n, int c[]) { int i,j,k; i=j=k=0; while(i<m && j<n ) if(a[i]<b[j]) c[k++] = a[i++]; else c[k++] = b[j++]; while(i<m) c[k++]= a[i++]; while(j<n) c[k++]= b[j++]; return; } int main() { int x[5],y[10],z[15]; cout<<"n ARRAY Xn"; input(x,5); cout<<"n ARRAY Yn"; input(y,10); concate(x,5,y,10,z); system("cls"); cout<<"n Array A : "; output(x,5); cout<<"n Array B : "; output(y,10); cout<<"n Merged Array : "; output(z,15); getch(); return 0;} Linear Search #include<iostream> #include<iomanip> #include<conio.h> using namespace std; 8
- 7. By : Rakesh Kumar D.A.V. Centenary Public School // function to read an array from the keyboard void input(int x[],int n) { for(int i=0;i<n;i++) { cout<<"Enter "<<i<<" element :"; cin>>x[i]; } return; } // function to display an arry on the screen void output(int x[],int n) { for(int i=0;i<n;i++) cout<<setw(6)<<x[i]; return; } // search an element using linear search int linear_search(int x[],int n,int data) { int i,found =0; for(i=0;i<n;i++) { if(x[i]==data) found =1; } return found; } int main() { int x[10],data; input(x,10); cout<<"n Enter element to search :"; cin>>data; int res = linear_search(x,10,data); cout<<"n Entered Array :"; output(x,10); if(res ==1) cout<<"n Given data available in given array "; else cout<<"n Given data not available in given array "; getch(); return 0; } Binary Search #include<iostream> #include<iomanip> #include<conio.h> using namespace std; // function to read an array from the keyboard void input(int x[],int n) { for(int i=0;i<n;i++) { cout<<"Enter "<<i<<" element :"; cin>>x[i]; } return; } // function to display an arry on the screen void output(int x[],int n) { 8
- 8. By : Rakesh Kumar D.A.V. Centenary Public School for(int i=0;i<n;i++) cout<<setw(6)<<x[i]; return; } // search an element using binary search int binary_search(int x[],int n,int data) { int first,last,mid ,found =0; first =0; last = n-1; while(first<=last && found ==0) { mid = (first+last)/2; if(x[mid] == data) found =1; else if(x[mid]>data) last = mid-1; else first = mid+1; } return found; } int main() { int x[10],data; input(x,10); cout<<"n Enter element to search :"; cin>>data; int res = binary_search(x,10,data); cout<<"n Entered Array :"; output(x,10); if(res ==1) cout<<"n Given data available in given array "; else cout<<"n Given data not available in given array "; getch(); return 0; } 8