#include <stdio.h>
#include <cs50.h>
#include <math.h>

int main(void){
    float input_amount;
    int pennies;
    int coins = 0;

    // Get the user input
    do {
        printf("Enter amount of change due: ");
        input_amount = get_float();

        if (input_amount < 0) {
            printf("You must enter a non-negative number. Try again.\n");
        }
    }
    while (input_amount < 0);

    // Get total amount of pennies input is equal to (multiply float by 100. Round as floats are imprecise (420 = 419.9999...)
    pennies = round(input_amount * 100);

    // Amount of 50p's that go into amount of pennies
    coins += pennies / 50;
    pennies %= 50;

    // Amount of 20p's that go into amount of pennies
    coins += pennies / 20;
    pennies %= 20;

    // Amount of 10p's that go into amount of pennies
    coins += pennies / 10;
    pennies %= 10;

    // Amount of 5p's that go into amount of pennies
    coins += pennies / 5;
    pennies %= 5;

    // Amount of 2's that go into amount of pennies
    coins += pennies / 2;
    pennies %= 2;

    // Amount of 1p's that go into amount of pennies
    coins += pennies / 1;
    pennies %= 1;

    printf("Minimum amount of coins required: %i\n", coins);
}