float fUSDValue;

float afRates[] = {
1.00,   // USD
2.3 // EUR
4.2 // GB
// . . 
// to nCurrenciesCount
};

for (int i=0; i<nCurrenciesCount;i++) {
  fRate = fUSD * afRates[i];
}

#include <stdio.h>

int main()
{
  char buffer[BUFSIZ];
  double EUR_per_USD = 1.3049; /* January 31, 2005, 1304 PST */

  double Number_of_Dollars;
  double Number_of_Euros;

  printf ("Enter the number of US Dollars to convert: ");
  if (!fgets(buffer, BUFSIZ, stdin)) {
    printf("Input error\n");
    return 1;
  }

  if (sscanf(buffer, "%lf", &Number_of_Dollars) != 1) {
    printf("Illegal input\n");
    return 1;
  }

  Number_of_Euros = Number_of_Dollars * EUR_per_USD;

  printf("\n\nThe number of Euros for %.2f US Dollars is %.2f\n", 
          Number_of_Dollars, Number_of_Euros);
  return 0;
}