5585 거스름돈

#include <stdio.h>
 
int money[6] = { 500,100,50,10,5,1 };
 
int main() {
    int total, idx = 0, rst = 0;
    scanf("%d", &total);
    
    total = 1000 - total;
 
    while (idx <= 5) {
        while (total >= money[idx]) {
            total -= money[idx];
            rst++;
        }
        idx++;
    }
 
    printf("%d", rst);
}