Java - 适用于搜索间隔的数据结构 [英] Java - Suitable data structure for search interval

问题描述

可能重复：

是否存在Java的开放式间隔实现？

我是Java的新手，我想知道什么是最好的数据结构，我如何搜索我的案例的数据结构：
我有int间隔，例如： 10-100,200-500,1000-5000，对于每个间隔，我有一个值1,2,3,4。
我想知道如何将所有这些间隔及其值保存在数据结构中并且如何搜索该数据结构以返回特定间隔的值。
例如如果我搜索15，那是间隔10-100，我想返回1。

I'm new to Java and i would like to know what is the best data structure and how can i search through that data structure for my case: I have int intervals eg: 10-100, 200-500, 1000-5000 and for each interval i have a value 1, 2, 3, 4. I would like to know how can i save all those intervals and their values in a data structure and how can i search through that data structure to return the value for the specific interval. Eg. if i search 15, that is in interval 10-100, i would like to return 1.

谢谢

推荐答案

我将使用这种方式：

import static org.hamcrest.core.Is.is;
import static org.junit.Assert.assertThat;

import org.junit.Test;

import java.util.ArrayList;
import java.util.List;

public class IntervalsTest {


    @Test
    public void shouldReturn1() {
        Intervals intervals = new Intervals();

        intervals.add(1, 10, 100);
        intervals.add(2, 200, 500);

        int result = intervals.findInterval(15);

        assertThat(result, is(1));

    }

    @Test
    public void shouldReturn2() {
        Intervals intervals = new Intervals();

        intervals.add(1, 10, 100);
        intervals.add(2, 200, 500);

        int result = intervals.findInterval(201);

        assertThat(result, is(2));

    }
}

class Range {

    private final int value;

    private final int lowerBound;

    private final int upperBound;


    Range(int value, int lowerBound, int upperBound) {
        this.value = value;
        this.lowerBound = lowerBound;
        this.upperBound = upperBound;
    }

    boolean includes(int givenValue) {
        return givenValue >= lowerBound && givenValue <= upperBound;

    }

    public int getValue() {
        return value;
    }
}

class Intervals {

    public List<Range> ranges = new ArrayList<Range>();

    void add(int value, int lowerBound, int upperBound) {
        add(new Range(value, lowerBound, upperBound));
    }

    void add(Range range) {
        this.ranges.add(range);
    }

    int findInterval(int givenValue) {
        for (Range range : ranges) {
            if(range.includes(givenValue)){
                return range.getValue();
            }
        }

        return 0; // nothing found // or exception
    }
}

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