I have a solution which is way faster and more simple than using the array

include

include

include

include

int main() {

int n;
scanf("%d", &n);
// Complete the code to print the pattern.
for (int i = 1; i <= 2 * n - 1; i++) {
    int d = abs(i - n);
    for(int j = 1; j <= n - 1 - d; j++) printf("%d ", n - j + 1);
    for(int j = 1; j <= 2 * d + 1; j++) printf("%d ", d + 1);
    for(int j = n - 1 - d; j >= 1; j--) printf("%d ", n - j + 1);
    printf("\n");

}
return 0;

}