variable sized array

1#include <cmath>
2#include <cstdio>
3#include <vector>
4#include <iostream>
5#include <algorithm>
6//using namespace std;
7
8
9int main() {
10    /* Enter your code here. Read input from STDIN. Print output to STDOUT */   
11    int n;                                  //number of Arrays
12    int q;                                  //number of Queries
13    int tempValue;                          //would be used to store the input value of each element in inner vector
14    
15    //storing the number of arrays in 'n' and number of queries in 'q'
16    std::cin >> n >> q;                    
17    
18    ////////////////////////
19    /*creation of vectors*/
20    //////////////////////
21    
22    //creating 'n' number of vector<int>
23    std::vector<std::vector<int>> a(n);
24    
25
26    int numberOfElements;                    //number of elements in each inner vector
27    //for each vector
28    for(int i = 0; i < n; i++){
29        //store the number of elements desired
30        std::cin >> numberOfElements;
31        //runs 'numberOfElements times
32        for(int j = 0; j < numberOfElements; j++){
33            std::cin >> tempValue;
34            a[i].push_back(tempValue);
35        }
36    }
37    
38    ///////////////////////
39    /*queries of vectors*/
40    /////////////////////
41    
42    int outVector;                          //stores the queried outer vector index
43    int inVector;                           //stores the queried inner vector index
44    //runs 'q' times
45    for(int i = 0; i < q; i++){
46        std::cin >> outVector >> inVector;
47        std::cout << a[outVector][inVector];
48        std::cout << std::endl;
49    }
50  
51    return 0;
52}
53