/in/foo.cc:11:0: warning: ignoring #pragma comment  [-Wunknown-pragmas]
 #pragma comment(linker, "/STACK:1024000000,1024000000")  // 扩栈
 
/in/foo.cc: In function 'int main()':
/in/foo.cc:131:22: warning: format '%d' expects argument of type 'int', but argument 2 has type 'll {aka long long int}' [-Wformat=]
     printf("%d\n",ans);
                      ^