fill_n() function in C++ STL with examples
The fill_n() function in C++ STL is used to fill some default values in a container. The fill_n() function is used to fill values upto first n positions from a starting position. It accepts an iterator begin and the number of positions n as arguments and fills the first n position starting from the position pointed by begin with the given value.
Syntax:
void fill_n(iterator begin, int n, type value);
Parameters:
- begin: The function will start filling values from the position pointed by the iterator begin.
- n: This parameter denotes the number of positions to be filled starting from the position pointed by first parameter begin.
- value: This parameter denotes the value to be filled by the function in the container.
Return Value: This function does not returns any value.
Below program illustrate the fill_n() function in C++ STL:
// C++ program to demonstrate working of fil_n() #include <bits/stdc++.h> using namespace std; int main() { vector< int > vect(8); // calling fill to initialize first four values // to 7 fill_n(vect.begin(), 4, 7); for ( int i = 0; i < vect.size(); i++) cout << ' ' << vect[i]; cout << '\n' ; // calling fill to initialize 3 elements from // "begin()+3" with value 4 fill_n(vect.begin() + 3, 3, 4); for ( int i = 0; i < vect.size(); i++) cout << ' ' << vect[i]; cout << '\n' ; return 0; } |
Output:
7 7 7 7 0 0 0 0 7 7 7 4 4 4 0 0
Reference: http://www.cplusplus.com/reference/algorithm/fill_n/
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