Find closest number to 0 in an array

#include<iostream>
using namespace std;
int main()
{
    int a[] = {2,-5,9,7,1};
    int b[5], temp;
    for(int i=0; i<5; i++)
    {
        b[i] = abs(a[i]);
    }
    for(int i=0; i<4; i++)
    {
        for(int j=0; j<4 ; j++)
        {
             if(b[j]>b[j+1])
             {
                 temp = b[j];
                 b[j] = b[j+1];
                 b[j+1] = temp;
             }
        }
       
    }
   cout<<b[0];
   return 0;
}