I have forgotten
my Password

Or login with:

  • Facebookhttp://facebook.com/
  • Googlehttps://www.google.com/accounts/o8/id
  • Yahoohttps://me.yahoo.com

//

Replaces n elements with a given value
+ View version details

Definition

The fill_n() algorithm is defined in the standard header <algorithm> and in the nonstandard backward-compatibility header <algo.h>.

Interface

#include <algorithm>
template < class OutputIterator, class Size, class Type >
   void fill_n(
      OutputIterator first, 
      Size count, 
      const Type& val
   );

Parameters:
Parameter Description
first An output iterator addressing the position of the first element in the range to be assigned the value val
count A signed or unsigned integer type specifying the number of elements to be assigned the value
val The value to be assigned to elements in the range [first, first + count)

Description

Fill_n algorithm does the same thing that fill but fills n elements.

Return Value

None.

Complexity

The complexity is linear; performs n assignments.
Example:

Example - fill_n function
Problem
The following program demonstrates how to use fill_n() function.
Workings
#include <vector>
#include <algorithm>
#include <iostream>
 
using namespace std;
 
int main()
{
  vector <int> vec;
  vector <int>::iterator Iter1;
  int i;
  for (i = 10; i <= 20; i++)
    vec.push_back(i);
  cout <<"Vector vec data: ";
  for (Iter1 = vec.begin(); Iter1 != vec.end(); Iter1++)
    cout <<*Iter1<<" ";
  cout <<endl;
  // fill the last 3 positions for 6 position with a value of 9
  cout <<"\nOperation: fill_n(vec.begin() + 3, 6, 9)\n";
  fill_n(vec.begin() + 3, 6, 9);
  cout <<"Modified vec data: ";
  for (Iter1 = vec.begin(); Iter1 != vec.end(); Iter1++)
    cout <<*Iter1<<" ";
   cout <<endl;
 
  return 0;
}
Solution
Output:

Vector vec data: 10 11 12 13 14 15 16 17 18 19 20
Operation: fill_n(vec.begin() + 3, 6, 9)
Modified vec data: 10 11 12 9 9 9 9 9 9 19 20
References