/in/foo.cc: In function 'int main()':
/in/foo.cc:23:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
   for(int j=0;j<a.length()-b.length()+1;){
                ^
/in/foo.cc:24:8: warning: unused variable 'tmp' [-Wunused-variable]
    int tmp=1;
        ^