什么是正确的Java数据结构和搜索算法来搜索一组IP范围以包含在内

TreeMap假设您没有重叠范围，则可以使用标准。

只需创建一个TreeMap，以范围的下限为键，并以整个范围作为值。使用查找范围，floorEntry(K key)并验证该值是否在范围内。

使用简单Integer而不是IpAddress对象的示例，但是任何Comparable对象都可以用作范围边界。

public final class RangeMap<T extends Comparable<T>> {
    private TreeMap<T, Range<T>> map = new TreeMap<>();
    public void add(Range<T> range) {
        Entry<T, Range<T>> entry = this.map.floorEntry(range.getUpperInclusive());
        if (entry != null && entry.getValue().overlaps(range))
            throw new IllegalArgumentException("Overlap: " + range + " vs " + entry.getValue());
        entry = this.map.ceilingEntry(range.getLowerInclusive());
        if (entry != null && entry.getValue().overlaps(range))
            throw new IllegalArgumentException("Overlap: " + range + " vs " + entry.getValue());
        this.map.put(range.getLowerInclusive(), range);
    }
    public boolean contains(T value) {
        Entry<T, Range<T>> entry = this.map.floorEntry(value);
        return (entry != null && entry.getValue().contains(value));
    }
    public Range<T> get(T value) {
        Entry<T, Range<T>> entry = this.map.floorEntry(value);
        return (entry != null && entry.getValue().contains(value) ? entry.getValue() : null);
    }
}
public final class Range<T extends Comparable<T>> {
    private final T lowerInclusive;
    private final T upperInclusive;
    public Range(T lowerInclusive, T upperInclusive) {
        this.lowerInclusive = lowerInclusive;
        this.upperInclusive = upperInclusive;
    }
    public T getLowerInclusive() {
        return this.lowerInclusive;
    }
    public T getUpperInclusive() {
        return this.upperInclusive;
    }
    public boolean contains(T value) {
        return (value.compareTo(this.lowerInclusive) >= 0 &&
                value.compareTo(this.upperInclusive) <= 0);
    }
    public boolean overlaps(Range<T> that) {
        return (this.lowerInclusive.compareTo(that.upperInclusive) <= 0 &&
                this.upperInclusive.compareTo(that.lowerInclusive) >= 0);
    }
    @Override
    public String toString() {
        return "(" + this.lowerInclusive + "-" + this.upperInclusive + ")";
    }
}

测试

RangeMap<Integer> map = new RangeMap<>();
map.add(new Range<>(50, 59));
map.add(new Range<>(70, 79));
for (int i = 40; i <= 90; i += 3)
    System.out.println(i + ": " + map.contains(i));

输出量

40: false
43: false
46: false
49: false
52: true
55: true
58: true
61: false
64: false
67: false
70: true
73: true
76: true
79: true
82: false
85: false
88: false

回答来源：Stack Overflow