Time limit exceed - c++

Question

The system said: my code was time limit exceed. Is there away to shortcut my code?
I'm using vector to save nails to graph.
Input: e,n
Output: checkcase=1 => Check u adjacent with i
checkcase=2 => find nails that around u
#include <iostream>
#include <vector>
#include <list>
#include <string>
using namespace std;
int main()
{
int e, n;
string u, i;
//using vectors
vector<string> graph;
//use list
list<string>listElementsInCase2;
cin >> e;
cin >> n;
//loop for e
for (long index = 0; index < e; index++)
{
cin>>u>> i;
//add u to graph
graph.push_back(u);
//add i to graph
graph.push_back(i);
}
//Option
int checkCase;
long index;
//loop for n
while(sizeof(n))
{
cin >> checkCase;
if (checkCase == 1)
{
cin >> u >> i;
for (index = 0; index < 2 * e; index += 2)
{ //Check u adjacent ? i
if ((graph.at(index) == u) && (graph.at(index + 1) == i))
{
cout << "TRUE" << endl;
break;
}
}
if (index == 2 * e)
cout << "FALSE" << endl;
}
//checkCase=2
if (checkCase == 2)
{
cin >> u;
for (long index = 0; index < 2 * e; index += 2)
{
if (graph.at(index) == u)
listElementsInCase2.push_back(graph.at(index + 1));
}
// return 0
if (listElementsInCase2.empty() == true)
cout << "0";
else
{
while (0 < listElementsInCase2.size())
{ //find nails that around u
cout << listElementsInCase2.front();
listElementsInCase2.pop_front();
cout << " ";
}
}
cout << endl;
}
n--;
}
}
//end

Answer 1

You seem to have an infinite while loop in your code.
Your statement while(sizeof(n)) will never stop repeating the loop since sizeof(n) always returns the byte size of the type integer, which is always a positive number and thus always evaluates as true.
A shortcut for your code would be to replace the while loop with a for or while loop that actually ends at some point. Also sizeof is probably not the function you want.
for(int i=0; i<n; i++){ might be what you are looking for.