一直显示：
Exception in thread "main" java.lang.IndexOutOfBoundsException: Index 1 out of bounds for length 1
at java.base/jdk.internal.util.Preconditions.outOfBounds(Preconditions.java:64)
at java.base/jdk.internal.util.Preconditions.outOfBoundsCheckIndex(Preconditions.java:70)
at java.base/jdk.internal.util.Preconditions.checkIndex(Preconditions.java:248)
at java.base/java.util.Objects.checkIndex(Objects.java:372)
at java.base/java.util.ArrayList.get(ArrayList.java:458)
at DailySchedue.DailySchedule.clearConflicts(DailySchedule.java:20)
at DailySchedue.DailySchedule.addAppt(DailySchedule.java:30)
at DailySchedue.Test.main(Test.java:9)