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  1. Prepare
  2. C++
  3. Introduction
  4. Variable Sized Arrays
  5. Discussions

Variable Sized Arrays

  • [deleted]     + 2 comments

    Hi, I'm fairly new to coding and don't really understand the concept of allocating memory. I just have a quick question - I was wondering why we had to allocate memory for the queries? My code looks similar to yours, except I only have 1 array: 

    #include <iostream> 
using namespace std;

int main() {
  int **a;         // create dynamic array
    int n, q ;     // number of rows, number of queries
    cin >> n >> q;
    
    a = new int* [n];
    for (int row = 0; row < n+1; row++) {            //go thru each row to enter variable length of col                                                       
        int k; cin >> k;          // # of columns for specific row
        a[row] = new int[k];
        
        for (int col = 0; col < k+1; col++)  {      // fill each column for specific row
            cin >> a[row] [col];
            
        }
        
    }
    
    
    for (int count = 0; count < q+1; count++ )  {   //fulfill queries
        int row; int col;                           
        cin >> row >> col;
        cout << a[row] [col];
        
    }

    

return 0;
}