CareerCup

Solution I suggest is this:
sort 1st array in increasing order and sort 2nd array in decreasing order.
this arrangement of the 2 arrays will result in min sum of product of corresponding elements, that is:
a1*b1 + a2*b2 + ...+ an*bn = minimum..

your take ?

This is the implementation of @IM.first idea.

#include<stdio.h>
#include<iostream>
#include<stdlib.h>
 
using namespace std;
 
#define N 5
 
int compare(const void *p1,const void *p2)  {
    
    return *(int *)p1-*(int *)p2;
    
}
 
int compare2(const void *p1,const void *p2) {
    return *(int *)p2-*(int *)p1;
}
 
 
int findMinimum(int *arr1,int *arr2)   {
    qsort(arr1,N,sizeof(int),compare);
    qsort(arr2,N,sizeof(int),compare2);
    int minimum=0;
    for(int i=0;i<N;i++)    {
        minimum+=arr1[i]*arr2[i];
    }
    return minimum;
}
 
int main()  {
    int arr1[]={3,2,7,4,-1};
    int arr2[]={4,12,10,8,9};
    cout<<"The minimum value is:"<<findMinimum(arr1,arr2);
    return 0;
}

what if both arrays contains negative numbers?
array1: -25,2,3,5
array 2: 23,-3,7,9
then ??

did you get through interview?

public class MinInnerProduct {
	public int solve(int[] array1,int[] array2){
		Arrays.sort(array1);
		Arrays.sort(array2);
		int toReturn=0;
		int negative1=negative(array1);
		int negative2=negative(array2);
		int l1=0;
		int r1=array1.length-1;
		int l2=0;
		int r2=array2.length-1;
		while(l1<=negative1 && r2>negative2){
			toReturn+=(array1[l1]*array2[r2]);
			l1++;
			r2--;
		}
		while(l2<=negative2 && r1>negative1){
			toReturn+=(array2[l2]*array1[r1]);
			l2++;
			r1--;
		}
		while(l1<=r1){
			toReturn+=array1[l1]*array2[l2];
			l1++;
		}
		return toReturn;
	}
	private int negative(int[] array){
		if(array[0]>=0){return -1;}
		
		for(int i=0;i<array.length;i++){
			if(array[i]>=0){
				return i-1;
			}
		}
		return array.length-1;
	}
	public static void main(String[] args){
		MinInnerProduct mip=new MinInnerProduct();
		int[] array1={-2,0,2};
		int[] array2={-2,-3,1};
		System.out.println(mip.solve(array1, array2));
	}
}

correct me if i did this wrong

public class C {

static int arr1[]={1,3,5,7,9};
static int arr2[]={10,8,6,4,2};

public static void main(String[] args) {

int min = 0;

for(int i=0;i<arr1.length;i++){

min += arr1[i] * arr2[i];
}

System.out.println(min);
}
}

what do you mean by arrange the array? I don't understand the question. You want to calculate the value or what?