java - 在一组范围中查找连接范围

Question

<分区>

Answer 1

为什么你需要一个图书馆？那不是那么多代码。

class Range{         
     int start , end;

     public Range(int start , int end){
          this.start = start;
          this.end = end;
     }
}

public static void join(List<Range> ranges){
     //sort the list ascending for easier comparison
     Collections.sort(ranges , (r1 , r2) -> {
          if(r1 < r2)return -1;
          else if(r1 > r2)return 1;
          else return 0;
     });

     int tmp = 1; //counter for the position in the list
     while(tmp < ranges.size()){
          if(ranges.get(tmp).start < ranges.get(tmp - 1).end){
                //the range at position tmp intersects with the previous 
                //one -> replace with the joined ranges
                Range r = new Range(ranges.get(tmp - 1).start , ranges.get(tmp).end);
                ranges.remove(tmp);
                ranges.remove(tmp - 1);
                ranges.add(r , tmp - 1);
           }else
                tmp++;//this pair (tmp - 1 / tmp) doesn't intersect -> next pair
     }
}