/in/foo.cc: In function 'int turn(std::__cxx11::string)':
/in/foo.cc:28:16: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  for (int i=0;i<s.size();i++) {
               ~^~~~~~~~~
/in/foo.cc: In function 'void Dijkstra()':
/in/foo.cc:44:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for (int j=0;j<a[i].size();j++) {
                 ~^~~~~~~~~~~~
/in/foo.cc:45:21: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
     if (a[i][j]=='+'&&x.s[j]=='0'||a[i][j]=='-'&&x.s[j]=='1') {
                      
/in/foo.cc:52:18: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
    for (int j=0;j<a[i].size();j++) {
                 ~^~~~~~~~~~~~