iterator example 2

#include <iostream>
#include <vector>
#include <iomanip>
using namespace std;
 
struct Tuple  {
    double attr1;
    double attr2;
};
 
int main() {
    double a = 1.0;
    vector<Tuple> vec(50, Tuple());
 
    for(vector<Tuple>::iterator it = vec.begin(); it != vec.end(); ++it) {
        it->attr1 = it->attr2 = a++;
    }
 
    Tuple arr[5][10];
    vector<Tuple>::iterator it = vec.begin();
    for(int i = 0; i < 5; ++i) {
        for(int j = 0; j < 10; ++j) {
            arr[i][j] = *it;
            ++it;
            cout << "(" << setw(2) << arr[i][j].attr1 << "," << setw(2) << arr[i][j].attr2 << ") ";
        }
        cout << '\n';
    }
    cout << endl;
}