Eroare de compilare: user.c:5:1: error: unknown type name ‘P’ P d[120001],c[120001],e[120001],b[120001]; ^ user.c: In function ‘A’: user.c:8:5: error: unknown type name ‘P’ P *c=(P*)a,*d=(P*)b; ^ user.c:8:11: error: ‘P’ undeclared (first use in this function) P *c=(P*)a,*d=(P*)b; ^ user.c:8:11: note: each undeclared identifier is reported only once for each function it appears in user.c:8:13: error: expected expression before ‘)’ token P *c=(P*)a,*d=(P*)b; ^ user.c:9:13: error: request for member ‘x’ in something not a structure or union return c->x<d->x||(c->x==d->x&&c->y<d->y); ^ user.c:9:18: error: request for member ‘x’ in something not a structure or union return c->x<d->x||(c->x==d->x&&c->y<d->y); ^ user.c:9:25: error: request for member ‘x’ in something not a structure or union return c->x<d->x||(c->x==d->x&&c->y<d->y); ^ user.c:9:31: error: request for member ‘x’ in something not a structure or union return c->x<d->x||(c->x==d->x&&c->y<d->y); ^ user.c:9:37: error: request for member ‘y’ in something not a structure or union return c->x<d->x||(c->x==d->x&&c->y<d->y); ^ user.c:9:42: error: request for member ‘y’ in something not a structure or union return c->x<d->x||(c->x==d->x&&c->y<d->y); ^ user.c: At top level: user.c:11:10: error: unknown type name ‘P’ double S(P a,P b,P p) { return (b.x-a.x)*(p.y-a.y)-(p.x-a.x)*(b.y-a.y); } ^ user.c:11:14: error: unknown type name ‘P’ double S(P a,P b,P p) { return (b.x-a.x)*(p.y-a.y)-(p.x-a.x)*(b.y-a.y); } ^ user.c:11:18: error: unknown type name ‘P’ double S(P a,P b,P p) { return (b.x-a.x)*(p.y-a.y)-(p.x-a.x)*(b.y-a.y); } ^ user.c: In function ‘main’: user.c:15:26: error: request for member ‘x’ in something not a structure or union scanf("%lf%lf",&d[i].x,&d[i].y); ^ user.c:15:34: error: request for member ‘y’ in something not a structure or union scanf("%lf%lf",&d[i].x,&d[i].y); ^ user.c:18:3: warning: implicit declaration of function ‘S’ [-Wimplicit-function-declaration]