Main.cc: In function ‘int main()’: Main.cc:5:24: error: ‘N’ was not declared in this scope int i, j, n, k = 1, a[N][N]; ^ Main.cc:10:4: error: ‘a’ was not declared in this scope a[i][j] = k++; ^ Main.cc:12:4: error: ‘a’ was not declared in this scope a[j][n - i - 1] = k++; ^ Main.cc:14:4: error: ‘a’ was not declared in this scope a[n - i - 1][j] = k++; ^ Main.cc:16:4: error: ‘a’ was not declared in this scope a[j][i] = k++; ^ Main.cc:21:18: error: ‘a’ was not declared in this scope printf("%5d", a[i][j]); ^ Main.cc:6:7: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result] scanf("%d", &n); ~~~~~^~~~~~~~~~