foo.cpp: In function 'int main()':
foo.cpp:10:11: error: 'aiii' was not declared in this scope
 double y1=aiii+bii+ci+d;
           ^
foo.cpp:10:16: error: 'bii' was not declared in this scope
 double y1=aiii+bii+ci+d;
                ^
foo.cpp:10:20: error: 'ci' was not declared in this scope
 double y1=aiii+bii+ci+d;
                    ^
foo.cpp:11:11: error: 'ajjj' was not declared in this scope
 double y2=ajjj+bjj+cj+d;
           ^
foo.cpp:11:16: error: 'bjj' was not declared in this scope
 double y2=ajjj+bjj+cj+d;
                ^
foo.cpp:11:20: error: 'cj' was not declared in this scope
 double y2=ajjj+bjj+cj+d;
                    ^
foo.cpp:12:11: warning: suggest parentheses around '&&' within '||' [-Wparentheses]
 if (y1>=0 && y2<=0||y1<=0 && y2>=0){
           ^