时间区间计算实现

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/**  * Created by shun on 2020/12/3.  * 时间区间 计算算法 实现  * 时间段的插入  * 时间段的删除  */ public class IntervalAlgorithm {         public static List<LocalDate[]> insertDate(List<LocalDate[]> intervals, LocalDate[] newInterval){         List<long[]> insert = insert(listToArray(intervals), new long[]{newInterval[0].toEpochDay(), newInterval[1].toEpochDay()});         return toDateList(insert);     }       public static List<LocalDate[]> removeDate(List<LocalDate[]> intervals, LocalDate[] toBeRemoved){         List<long[]> removed = removeInterval(listToArray(intervals), new long[]{toBeRemoved[0].toEpochDay(), toBeRemoved[1].toEpochDay()});         return toDateList(removed);     }       /**      * 插入新的时间区间      * @param intervals 已有区间      * @param newInterval 新区间      * @return 插入后的新区间      */     public static List<long[]> insert(long[][] intervals, long[] newInterval) {         long left = newInterval[0];         long right = newInterval[1];         boolean placed = false;         List<long[]> ansList = new ArrayList<long[]>();         for (long[] interval : intervals) {             if (interval[0] > right) {                 // 在插入区间的右侧且无交集                 if (!placed) {                     addInterval(ansList, new long[]{left, right});                     placed = true;                 }                 addInterval(ansList, interval);             } else if (interval[1] < left) {                 // 在插入区间的左侧且无交集                 addInterval(ansList, interval);             } else {                 // 与插入区间有交集，计算它们的并集                 left = Math.min(left, interval[0]);                 right = Math.max(right, interval[1]);             }         }         if (!placed) {             addInterval(ansList, new long[]{left, right});         } //        LocalDate[][] ans = new LocalDate[ansList.size()][2]; //        for (int i = 0; i < ansList.size(); ++i) { //            ans[i] = ansList.get(i); //        }         return ansList;     }         /**      * 删除区间      * @param intervals      * @param toBeRemoved      * @return      */     public static List<long[]> removeInterval(long[][] intervals, long[] toBeRemoved) {         List<long[]> res = new ArrayList();         for (long[] inter : intervals) {             if (inter[1] <= toBeRemoved[0] || inter[0] >= toBeRemoved[1]) {//不再区间就不变                 addInterval(res, new long[]{inter[0], inter[1]});             } else {                 //在区间                 if (inter[0] < toBeRemoved[0] ) addInterval(res, new long[]{inter[0], toBeRemoved[0]});//右相交                 if (inter[1] > toBeRemoved[1] ) addInterval(res, new long[]{toBeRemoved[1], inter[1]});//左相交             }         }           return res;     }         private static long[][] listToArray( List<LocalDate[]> list){         long[][] ans = new long[list.size()][2];         for (int i = 0; i < list.size(); ++i) {             ans[i] = new long[]{list.get(i)[0].toEpochDay(), list.get(i)[1].toEpochDay()};         }         return ans;     }       public static List<LocalDate[]> toDateList(List<long[]> array){         List<LocalDate[]> list = Lists.newArrayList();         for (int i = 0; i < array.size(); i++) {             list.add( new LocalDate[]{LocalDate.ofEpochDay(array.get(i)[0]), LocalDate.ofEpochDay(array.get(i)[1])});         }         return list;     }       //过滤掉当前时间以前的区间     private static void addInterval(List<long[]> list, long[] newInterval){         if (newInterval[1] > LocalDate.now().toEpochDay() ){             if (newInterval[0] < LocalDate.now().toEpochDay()) {                 newInterval[0] = LocalDate.now().toEpochDay();             }             list.add(newInterval);         }     }         public static void main(String[] args) {         List<LocalDate[]> removeInterval = IntervalAlgorithm.removeDate(                 Lists.newArrayList(                         new LocalDate[]{LocalDate.of(2019, 01, 01), LocalDate.of(2020, 03, 01)},                         new LocalDate[]{LocalDate.of(2021, 01, 01), LocalDate.of(2021, 03, 01)},                         new LocalDate[]{LocalDate.of(2021, 05, 01), LocalDate.of(9999, 01, 01)}                         ),                 new LocalDate[]{LocalDate.of(2021, 06, 01), LocalDate.of(9999, 01, 01)}         );           System.out.println(JSON.toJSONString(removeInterval));             List<LocalDate[]> insert = IntervalAlgorithm.insertDate(                 removeInterval,                 new LocalDate[]{LocalDate.of(2021, 06, 01), LocalDate.of(9999, 01, 01)});             System.out.println(JSON.toJSONString(insert));     }   }