foo.cc: In function 'void solve()':
foo.cc:44:9: warning: this 'for' clause does not guard... [-Wmisleading-indentation]
   44 |         for(len=0;(1<<len)<=lim;len++);lim=(1<<len);len--;
      |         ^~~
foo.cc:44:40: note: ...this statement, but the latter is misleadingly indented as if it were guarded by the 'for'
   44 |         for(len=0;(1<<len)<=lim;len++);lim=(1<<len);len--;
      |                                        ^~~
foo.cc: In function 'int main()':
foo.cc:68:7: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   68 | {scanf("%d",&T);for(int z=1;z<=T;z++){solve();clear();}return 0;//拜拜程序~
      |  ~~~~~^~~~~~~~~
foo.cc: In function 'void solve()':
foo.cc:41:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   41 |     scanf("%d%d",&x,&y);lim=x*y;
      |     ~~~~~^~~~~~~~~~~~~~
foo.cc:51:30: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   51 |             int a;int b;scanf("%d%d",&a,&b);db ret=0;
      |                         ~~~~~^~~~~~~~~~~~~~
foo.cc:61:28: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   61 |             db a;db b;scanf("%lf%lf",&a,&b);
      |                       ~~~~~^~~~~~~~~~~~~~~~

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