Compilare: user.c: In function ‘main’: user.c:82:5: warning: implicit declaration of function ‘malloc’ [-Wimplicit-function-declaration] coord* C = (coord*)malloc(n * sizeof(coord)); ^ user.c:82:24: warning: incompatible implicit declaration of built-in function ‘malloc’ [enabled by default] coord* C = (coord*)malloc(n * sizeof(coord)); ^