C++ Programming Code Examples
C++ > Algorithms Code Examples
Merge Sort
/* Merge Sort */
#include <iostream.h>
int a[50];
void merge(int,int,int);
void merge_sort(int low,int high)
{
int mid;
if(low<high)
{
mid=(low+high)/2;
merge_sort(low,mid);
merge_sort(mid+1,high);
merge(low,mid,high);
}
}
void merge(int low,int mid,int high)
{
int h,i,j,b[50],k;
h=low;
i=low;
j=mid+1;
while((h<=mid)&&(j<=high))
{
if(a[h]<=a[j])
{
b[i]=a[h];
h++;
}
else
{
b[i]=a[j];
j++;
}
i++;
}
if(h>mid)
{
for(k=j;k<=high;k++)
{
b[i]=a[k];
i++;
}
}
else
{
for(k=h;k<=mid;k++)
{
b[i]=a[k];
i++;
}
}
for(k=low;k<=high;k++) a[k]=b[k];
}
void main()
{
int num,i;
cout<<"***************************************************"<<endl;
cout<<" MERGE SORT PROGRAM
"<<endl;
cout<<"*******************************************************"<<endl;
cout<<endl<<endl;
cout<<"Please Enter THE NUMBER OF ELEMENTS you want to sort [THEN
PRESS
ENTER]:"<<endl;
cin>>num;
cout<<endl;
cout<<"Now, Please Enter the ( "<< num <<" ) numbers (ELEMENTS) [THEN
PRESS ENTER]:"<<endl;
for(i=1;i<=num;i++)
{
cin>>a[i] ;
}
merge_sort(1,num);
cout<<endl;
cout<<"So, the sorted list (using MERGE SORT) will be :"<<endl;
cout<<endl<<endl;
for(i=1;i<=num;i++)
cout<<a[i]<<" ";
cout<<endl<<endl<<endl<<endl;
}
The cin object is used to accept input from the standard input device i.e. keyboard. It is defined in the iostream header file. C++ cin statement is the instance of the class istream and is used to read input from the standard input device which is usually a keyboard. The extraction operator(>>) is used along with the object cin for reading inputs. The extraction operator extracts the data from the object cin which is entered using the keyboard. The "c" in cin refers to "character" and "in" means "input". Hence cin means "character input". The cin object is used along with the extraction operator >> in order to receive a stream of characters.
In computer programming, loops are used to repeat a block of code. For example, when you are displaying number from 1 to 100 you may want set the value of a variable to 1 and display it 100 times, increasing its value by 1 on each loop iteration. When you know exactly how many times you want to loop through a block of code, use the for loop instead of a while loop. A for loop is a repetition control structure that allows you to efficiently write a loop that needs to execute a specific number of times.
A predefined object of the class called iostream class is used to insert the new line characters while flushing the stream is called endl in C++. This endl is similar to \n which performs the functionality of inserting new line characters but it does not flush the stream whereas endl does the job of inserting the new line characters while flushing the stream. Hence the statement cout<<endl; will be equal to the statement cout<< '\n' << flush; meaning the new line character used along with flush explicitly becomes equivalent to the endl statement in C++.
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Return true if "empty"; else false. Remove all items. Return position to prior to first. Return "first position". Insert x after "current iterator" position p. Return position that views. ListItr
The 'C++ program' tries to count alphabetical letters from d to n, but a break makes it stop when it encounters k: In a for statement, the 'break' can stop the counting when particular
