/in/foo.cc: In function 'void mergesort(int)':
/in/foo.cc:28:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int j=0;j<v[i].size();j++)
~^~~~~~~~~~~~
/in/foo.cc:34:17: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
for(int j=0;j<v1[i].size();j++)
~^~~~~~~~~~~~~
/in/foo.cc:31:6: warning: unused variable 'k' [-Wunused-variable]
int k,t=0;
^
/in/foo.cc:31:8: warning: unused variable 't' [-Wunused-variable]
int k,t=0;
^