509A Maximum in Table

1. #include <iostream>
2. using namespace std;
3. int a, arr[10][10];
4. int main() {
5. cin >> a;
6. for (int i = 0; i < a; i++) {
7. for (int j = 0; j < a; j++) {
8. if (i == 0) {
9. arr[i][j] = 1;
10. } else if (j == 0) {
11. arr[i][j] = 1;
12. } else {
13. arr[i][j] = arr[i - 1][j] + arr[i][j - 1];
14.  
15. }
16. }
17. }
18. cout << arr[a - 1][a - 1];
19. }