Have a look at the code below all three print statements at the end of main function are giving different results, can someone please explain why is it so??

Input :: 4 4 3 4 3 2 1 1 0.3 3 1 4 0.6 5 3 4 2 1 3 5 3 0.8 4 0.6 5 0.3 6 5 1 3 2 4 5 6 4 0.9 5 0.3 2 0.4 6 0.7 3 0.5 4 2 1 2 3 4 2 0.5 4 0.1

code::

void MAIN() { int n,m; cin>>n>>m; int x=0; for(int i=1;i<=n;i++) { int a;

cin>>a;

    if(a!=i)
    {
        x=i;
    }
}

float arr[n+1]={0};
for(int i=1;i<=m;i++)
{
    int a;
    cin>>a;
    float b;
    cin>>b;
    arr[a]=b;



}

if(x==0)
{
    cout<<1<<endl;
    return;
}

float p=1.0;
float ans=0;
for(int i=n;i>=x;i-- )
{
    ans+=p*arr[i];
    p*=(1.0-arr[i]);

}

//printf("%f\n", ans); cout<<ans<<"\n"; //cout<<ans<<endl;

}

int main() { #ifndef ONLINE_JUDGE freopen("input.txt", "r", stdin); freopen("output.txt", "w", stdout); #endif ios_base::sync_with_stdio(false); cin.tie(NULL);

int t;
cin>>t;
while(t--)
{
     MAIN();
}

}