8 of 12 problem title

# Aliens at the train

I solved this problem on spoj and was just on the border of time limit. I want to know any improvements for my code in context of competitive programming and c/c++ language.

How can I speed up the I/O and how can I shorten my code?

#include <cstdio>
#include <deque>
using namespace std;

int main()
{
int t,siz;
scanf("%d",&t);
long long int at,bt,sum=0,max=0,maxsum=0,peep=0;
deque<int> people;
while(t--){
sum=max=maxsum=peep=0;
people.clear();
scanf("%lld%lld",&at,&bt);
while(at--){
scanf("%lld",&peep);
people.push_back(peep);
if(sum+peep<=bt)
{
sum+=peep;
}
else{
siz=people.size()-1;
if(max==siz){
maxsum=maxsum<sum?maxsum:sum;
}
else if(max<siz){
maxsum=sum;
max=siz;
}
sum+=peep;
while(sum>bt){
sum-=people.front();
people.pop_front();
}
}
}
siz=people.size();
if(max==siz){
maxsum=maxsum<sum?maxsum:sum;
}
else if(max<siz){
maxsum=sum;
max=siz;
}
printf("%lld %lld\n",maxsum,max);
}
return 0;
}