Compilare: user.c: In function ‘main’: user.c:74:5: warning: implicit declaration of function ‘malloc’ [-Wimplicit-function-declaration] point* P = (point*)malloc(sizeof(point) * n); ^ user.c:74:24: warning: incompatible implicit declaration of built-in function ‘malloc’ [enabled by default] point* P = (point*)malloc(sizeof(point) * n); ^