src/main/java/com/fishercoder/solutions/_1904.java

package com.fishercoder.solutions;

public class _1904 {
    public static class Solution1 {
        public int numberOfRounds(String startTime, String finishTime) {
            int rounds = 0;
            int startHour = Integer.parseInt(startTime.split(":")[0]);
            int endHour = Integer.parseInt(finishTime.split(":")[0]);
            int startMin = Integer.parseInt(startTime.split(":")[1]);
            int endMin = Integer.parseInt(finishTime.split(":")[1]);
            if (endHour < startHour) {
                endHour += 24;
            } else if (endHour == startHour && endMin < startMin) {
                endHour += 24;
            }
            if (startHour == endHour) {
                if (startMin == 0 && endMin >= 15) {
                    rounds++;
                }
                if (startMin <= 15 && endMin >= 30) {
                    rounds++;
                }
                if (startMin <= 30 && endMin >= 45) {
                    rounds++;
                }
                return rounds;
            } else {
                //compute all full rounds in the start hour
                if (startMin == 0) {
                    rounds += 4;
                } else if (startMin <= 15) {
                    rounds += 3;
                } else if (startMin <= 30) {
                    rounds += 2;
                } else if (startMin <= 45) {
                    rounds++;
                }

                //compute all full rounds in the finish hour
                if (endMin >= 45) {
                    rounds += 3;
                } else if (endMin >= 30) {
                    rounds += 2;
                } else if (endMin >= 15) {
                    rounds++;
                }

                //compute all full rounds in the all full hours between finishHour and startHour
                rounds += (endHour - startHour - 1) * 4;
                return rounds;
            }
        }
    }
}