c++ standard library fill_n demo

#include <iostream>
#include <vector>
#include <algorithm>

using namespace std;

int main()
{
vector<int> ivec(10, 9);
fill_n(ivec.begin(), 3, 0);

for (vector<int>::iterator it = ivec.begin(); it != ivec.end(); ++it)
{
cout << *it << " ";
}
cout << endl;

return 0;
}