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import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
public class Ch1 {
public static void main(String[] args) {
ArrayList<Integer> arr1 = new ArrayList<>(List.of(5,5,5,10,20));
ArrayList<Integer> arr2 = new ArrayList<>(List.of(5,5,10,10,20));
ArrayList<Integer> arr3 = new ArrayList<>(List.of(5,5,5,20));
System.out.println(exact_change(arr1));
System.out.println(exact_change(arr2));
System.out.println(exact_change(arr3));
}
private static boolean exact_change(List<Integer> list) {
HashMap<Integer,Integer> m = new HashMap<Integer,Integer>();
for(var e : list)
{
if(e == 10)
{
m.replace(5, m.get(5) - 1);
if(m.get(5) == 0) return false;
}
else if(e == 20)
{
if(m.getOrDefault(5,0) != 0 &&
m.getOrDefault(10,0) != 0)
{
m.replace(5,m.get(5)-1);
m.replace(10,m.get(10)-1);
}
else if(m.get(5) > 2) m.replace(5,m.get(5)-3);
else return false;
}
m.put(e,m.getOrDefault(e,0)+1);
}
return true;
}
}
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