void foo(int *a1, int w, int h) {
   int *a2 = malloc(sizeof(int)*w*h);
   memcpy(a2, a1, sizeof(int)*w*h);
   int row, col;
   for(row=0; row<h; row++) for(col=0; col<w; col++) {
      printf("%d ", a2[row*w + col]);
  }
   free(a2);
}

int main() {
   int arr[10][20];
   a[5][6] = 1234;
   foo(arr, 10, 20);
   return 0;
}

#include<array>
#include<iostream>

template<size_t N, size_t M> 
void func(std::array<std::array<int, M>, N> arr) {
    for(auto const& i: arr) { 
        for(auto const& k: i) std::cout << k << ", "; 
        std::cout << std::endl; 
    }
}

int main() {
   std::array<std::array<int, 10>, 20> arr;
   for(auto &i: arr) for(auto &k: i) k = 0;
   arr[5][6] = 1234;
   func(arr);
   return 0;
}