greedy

while ( change > 0 ) {
    if ( change >= 25 ) {
        change -= 25;
    } else if ( change >= 10 && change < 25 ) {
        change -= 10;
    } else if ( change >= 5 && change < 10 ) {
        change -= 5;
    } else {
        change -= 1;
    }
    coins++;
}