/in/foo.cc: In function 'int main()':
/in/foo.cc:29:24: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   if(A[0]>=11||B[0]>=11&&abs(A[0]-B[0])>=2) {
                ~~~~~~~~^~~~~~~~~~~~~~~~~~~
/in/foo.cc:33:24: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
   if(A[1]>=21||B[1]>=21&&abs(A[1]-B[1])>=2) {
                ~~~~~~~~^~~~~~~~~~~~~~~~~~~
/in/foo.cc:42:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<v1.size(); i++) {
               ~^~~~~~~~~~
/in/foo.cc:46:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for(int i=0; i<v2.size(); i++) {
               ~^~~~~~~~~~