[redhead]

Ok, you convinced me.. .I'll do the start part, you can then complete it...

#include <iostream>

int main()
{
  int amount=-1;
  while(amount < 0){
    std::cout << "Input amount of pennies: " ;
    std::cout.flush();
    std::cin >> amount;
    if(amount < 0)
        std::cout << "It's impossible to have negative amount" << std::endl;
  }
  if(amount >= 100){
    std::cout << "Dollars:\t" << amount/100 << std::endl;
    amount = amount %100;
  }
  if(amount >= 25){
    /* now you continue */