/in/foo.cc: In function 'int main()':
/in/foo.cc:35:16: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
    else if(xs<0&&2*a>0||xs>0&&2*a>0)cout<<xs<<'/'<<2*a<<endl;
            ~~~~^~~~~~~
/in/foo.cc:36:16: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
    else if(xs>0&&2*a<0||xs<0&&2*a<0)cout<<-xs<<'/'<<-2*a<<endl;
            ~~~~^~~~~~~
/in/foo.cc:43:11: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
    if(zi<0&&mu>0||zi>0&&mu>0)cout<<zi<<'/'<<mu<<endl;
       ~~~~^~~~~~
/in/foo.cc:44:16: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
    else if(zi>0&&mu<0||zi<0&&mu<0)cout<<-zi<<'/'<<-mu<<endl;
            ~~~~^~~~~~
/in/foo.cc:58:16: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
    else if(k1<0&&k3>0||k1>0&&k3>0)cout<<k1<<'/'<<k3<<endl;
            ~~~~^~~~~~
/in/foo.cc:59:16: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
    else if(k1<0&&k3<0||k1>0&&k3<0)cout<<-k1<<'/'<<-k3<<endl;
            ~~~~^~~~~~
/in/foo.cc:48:19: warning: variable 'lef' set but not used [-Wunused-but-set-variable]
    int xs=INT_MIN,lef=0;
                   ^~~
/in/foo.cc:55:11: warning: variable 'k2' set but not used [-Wunused-but-set-variable]
    int k1,k2,k3;
           ^~