insert function in c++ vector
// Program below illustrates the
// vector::insert() function
#include <bits/stdc++.h>
using namespace std;
int main()
{
// initialising the vector
vector<int> vec = { 10, 20, 30, 40 };
// inserts 3 at front
auto it = vec.insert(vec.begin(), 3);
// inserts 2 at front
vec.insert(it, 2);
int i = 2;
// inserts 7 at i-th index
it = vec.insert(vec.begin() + i, 7);
cout << "The vector elements are: ";
for (auto it = vec.begin(); it != vec.end(); ++it)
cout << *it << " ";
return 0;
}
// inserting into a vector
#include <iostream>
#include <vector>
int main ()
{
std::vector<int> myvector (3,100);
std::vector<int>::iterator it;
it = myvector.begin();
it = myvector.insert ( it , 200 );
myvector.insert (it,2,300);
// "it" no longer valid, get a new one:
it = myvector.begin();
std::vector<int> anothervector (2,400);
myvector.insert (it+2,anothervector.begin(),anothervector.end());
int myarray [] = { 501,502,503 };
myvector.insert (myvector.begin(), myarray, myarray+3);
std::cout << "myvector contains:";
for (it=myvector.begin(); it<myvector.end(); it++)
std::cout << ' ' << *it;
std::cout << '\n';
return 0;
}