Given an array of positive integers, rearrange them so that they together form the largest number

#include<iostream>

#define SIZE 4
using namespace std;

bool decide(int a,int b)
{
    int ta=a,tb=b;
    int pa=1,pb=1;
    while(a>0)
    {
        a/=10;
        pa*=10;
    }
    while(b>0)
    {
        b/=10;
        pb*=10;
    }
    int a_b=ta*pb+tb;//Append b after a.
    int b_a=tb*pa+ta;//Append a after b.
    if(a_b>b_a)
    {
        return false;
    }
    else
    {
        return true;
    }
}

int main()
{
    int A[SIZE]={87,181,9,5};
    //Use any sorting technique but the decide function is the key.
    for(int i=0;i<SIZE;i++)
    {
        for(int j=0;j<SIZE-i-1;j++)
        {
            if(decide(A[j],A[j+1]))
            {
                int t=A[j];
                A[j]=A[j+1];
                A[j+1]=t;
            }
        }
    }
    for(int i=0;i<SIZE;i++)
    {
        cout<<A[i]<<" ";
    }
    cout<<endl;
}
Input:
87 181 9 5
Output:
9 87 5 181