Description : Sets a number of elements of a range (i.e, vector) to a value. The function takes 3 arguments. The iterator of the range, the number of elements to set starting from the iterator's first element and the new value.
Example :
#include <iostream>
#include <vector>
#include <algorithm>
void print_vector(const std::vector<int> &v) {
// iterate through v and print its elements
for(auto &elem:v) {
std::cout << elem << " ";
}
std::cout<<std::endl;
}
int main() {
std::vector<int> v = {1,1,1,1,1,1,1,1};
std::cout << "Before fill_n: ";
print_vector(v);
// set the first half of v's elements to zero
std::fill_n(v.begin(), v.size()/2, 0);
std::cout << "After fill_n: ";
print_vector(v);
return 0;
}