Segmentation fault: 11 in C++ program [on hold]

I'm getting a segmentation fault in my C++ program, kindly help me know where I'm going wrong. Code is as follows:

#include<iostream>
#include<fstream>
#include <stdlib.h>
using namespace std;


int hasTwoElements(int A[], int n, int x)
{
    int temp;
    bool hashMap[2000] = {0}; /*initialize hash map as 0*/

    for (int i = 0; i < n; i++)
    {
        temp = x - A[i];
        if (temp >= 0 && hashMap[temp] == 1)
    return 1;
    hashMap[A[i]] = 1;
}
return 0;
}


int main()
{
    ofstream input,output;
    input.open ("ip.txt");
    output.open ("op.txt");
    int t;
    cin>>t;
    input<<t<<endl;
    while(t--){
       int n=rand()%50+1;
       int A[n];
       input<<n<<endl;
       for(int i=0;i<n;i++){
           A[i] = rand()%1000-500;
           input<<A[i]<<" ";
       }
       input<<endl;
       int x;
       x = rand()%2000-1000;
       input<<x<<endl;
       if(hasTwoElements(A, n, x)==1)
          output<<"Pair exists"<<endl;
       else
          output<<"Pair doesn't exist"<<endl;
    }
output.close();
input.close();
return 0;
}

I'm basically trying to check if a pair exists in the array for which the sum of the two numbers is equal to the number X passed in the function.