Compilare: main.cpp: In function 'int main()': main.cpp:47:29: warning: 'dif2' may be used uninitialized in this function [-Wmaybe-uninitialized] if((y-y1)*dif1 == (x-x1)*dif2) ~~~~~~^~~~~ main.cpp:59:20: note: 'dif2' was declared here int x1,y1,dif1,dif2; ^~~~ main.cpp:47:14: warning: 'dif1' may be used uninitialized in this function [-Wmaybe-uninitialized] if((y-y1)*dif1 == (x-x1)*dif2) ~~~~~~^~~~~ main.cpp:59:15: note: 'dif1' was declared here int x1,y1,dif1,dif2; ^~~~ main.cpp:47:10: warning: 'y1' may be used uninitialized in this function [-Wmaybe-uninitialized] if((y-y1)*dif1 == (x-x1)*dif2) ~~^~~~ main.cpp:59:12: note: 'y1' was declared here int x1,y1,dif1,dif2; ^~ main.cpp:47:25: warning: 'x1' may be used uninitialized in this function [-Wmaybe-uninitialized] if((y-y1)*dif1 == (x-x1)*dif2) ~~^~~~ main.cpp:59:9: note: 'x1' was declared here int x1,y1,dif1,dif2; ^~