/in/foo.cc: In function 'int main()':
/in/foo.cc:8:23: warning: format '%d' expects argument of type 'int*', but argument 2 has type 'long long int*' [-Wformat=]
   scanf("%1d",&a[i][i]);
                       ^
/in/foo.cc:22:21: warning: format '%d' expects argument of type 'int', but argument 2 has type 'long long int' [-Wformat=]
  printf("%d",f[n][k]);
                     ^