# Variable Sized Arrays – HackerRank Solution ### Problem :

Consider an `n`-element array, `a`, where each index `i` in the array contains a reference to an array of `ki` integers (where the value of `ki` varies from array to array). See the Explanation section below for a diagram.

Given `a`, you must answer `q` queries. Each query is in the format `i j`, where `i` denotes an index in array `a` and `i` denotes an index in the array located at `a[i]`. For each query, find and print the value of element `j` in the array at location `a[i]` on a new line.

Click here to know more about how to create variable sized arrays in C++.

Sample Input :

``````2 2
3 1 5 4
5 1 2 8 9 3
0 1
1 3``````

Sample Output :

``````5
9``````

### Solution :

``````#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
int main() {
int n; int q;
cin >> n >> q;
vector<int> a[n];
int c; int b;
for(int i = 0; i < n; i++) {
cin >> b;
for (int j = 0; j < b; j++) {
cin >> c;
a[i].push_back(c);
}
}
int d; int e;
for(int i = 0; i < q; i++) {
cin >> d >> e;
cout << a[d][e] << endl;
}

return 0;
}``````

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