WA in FAMWEALT

[checks]

Initially I am simply building the tree...(going up from x to the root via x's ancestors)
and then coming down I am calculating the value of every node till y. Can someone please point out the mistake in my code..

#include<iostream>
#include<cstdio>
#include<iomanip>
using namespace std;
long double a[1000010];
int main()
{
        int tc;
        cin>>tc;
        while(tc--)
        {
                int x,y,w;
                cin>>x>>y>>w;
                if(x%2==0)
                        w*=2;
                a[x]=w;
                int i=x;
                while(i/2>0)
                {
                        if((i/2)%2==0)
                        {
                                if(i%2==0)
                                {
                                        a[i/2]=a[i];
                                }
                                else
                                        a[i/2]=2.0*a[i];
                        }
                        else
                        {
                                if(i%2==0)
                                {
                                        a[i/2]=2.0*a[i];
                                }
                                else
                                        a[i/2]=4.0*a[i];
                        }
                        i/=2;
                }
                i=1;
            while(i<=y/2)
            {
                    if(i%2)
                    {
                            a[2*i]=a[i]/2;
                            a[2*i + 1]=a[i]/4;
                    }
                    else
                    {
                            a[2*i]=a[i];
                            a[2*i+1]=a[i]/2;
                    }
                    i++;
            }
            cout<<fixed<<setprecision(6)<<a[y]<<endl;
    }
}