/in/foo.cc: In function 'sen readsen()':
/in/foo.cc:105:1: warning: control reaches end of non-void function [-Wreturn-type]
 }
 ^
/in/foo.cc: In function 'int main()':
/in/foo.cc:150:22: warning: 'tmp' may be used uninitialized in this function [-Wmaybe-uninitialized]
     else if(p[a[k].w]!=tmp)
             ~~~~~~~~~^~~~~