To minimizing the sum of two distances from the number

Question

I have a homework. The homework is like that

There is the number X, and array A and array B whose data type is int. and I should find the A[I]+B[J](0<=I<=A.length, 0<=J<=B.length) which is closest to X.

First, I tried to find the answer by testing All I&J. but there is time limit and memory limit. So I made a hypothesis the number which is larger than X is not needed. However, I faced at the time limit exceed problem again. How can I save the time?

my code is this.

import java.util.Scanner;
import java.lang.Math;

public class PRO_D{
public static void main(String[] args)
{
    Scanner kb=new Scanner(System.in);
    int aLen=kb.nextInt();
    int bLen=kb.nextInt();
    long number=kb.nextLong();
    long distance=100;
    long dist=100;
    int aCnt=0, bCnt=0;
    long temp;

    kb.nextLine();

    long[] arrA=new long[aLen];
    long[] arrB=new long[bLen];

    for(int i=0; i<aLen; i++)
    {
        temp = kb.nextLong();
        if (temp <= number)
        {
            if(number-temp<distance)
            {
                distance=number-temp;
            }
            arrA[i] = temp;
            aCnt++;
        }
        else if(number-temp<distance)
        {
            arrA[i]=temp;
            aCnt++;
        }
    }

    for(int i=0; i<bLen; i++)
    {
        temp = kb.nextLong();
        if (temp <= number)
        {
            if(number-temp<distance)
            {
                distance=number-temp;
            }
            arrB[i] = temp;
            bCnt++;
        }
        else if(number-temp<distance)
        {
            arrB[i]=temp;
            bCnt++;
        }
    }

    for(int i=0; i<aCnt; i++)
        for(int j=0; j<bCnt; j++)
        {
            temp=Math.abs(number-arrA[i]-arrB[j]);
            if(dist>temp)
                dist=temp;
        }
    System.out.println(dist);
}

Are they all positive numbers? What is the time limit & memory limit? — Bon, Oct 25 '15 at 15:52
We'll need to see your algorithm, to determine what could be better or worse. — dcgenjin, Oct 25 '15 at 15:53
numbers are either positive or negative. they are not sorted. time limit is 1s and memory limit is 128mb. And I edited my questions with codes. — Volnyar, Oct 25 '15 at 16:19

score 0 · Answer 1 · answered Oct 25 '15 at 16:41

0

If the arrays are sorted a modified binary search that keeps track of the distances might work.

answered Oct 25 '15 at 16:41

Subito

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To minimizing the sum of two distances from the number

1 Answers1