fr.c

#include <stdio.h>
#include <stdlib.h>
 
typedef struct hrana {
	struct hrana *next;
	struct vrchol *vrchol;
} Hrana;
 
typedef struct vrchol {
	int val;
	int uzav;
	struct hrana *hrana;		
} Vrchol;
 
Vrchol* vytvor(int val, int uzav) {
	Vrchol *v = (Vrchol *) malloc(sizeof(Vrchol));
	v->val = val;
	v->uzav = uzav;
	v->hrana = NULL;
	return v;
}
 
Vrchol* hladaj(Vrchol *v, int A, int B) {
	Vrchol *p;
	if (v->val == A || v->val == B) {
		return v;
	}
	else {
		Hrana *hrana = v->hrana;
		while (hrana != NULL) {
			p = hladaj(hrana->vrchol, A, B);
			if(p!=NULL)
				return p;
			hrana = hrana->next;
		}
	}
	return NULL;
}
 
void pridaj(Vrchol* v, int A, int B, int uzav) {
		Hrana *nova = (Hrana *) malloc(sizeof(Hrana));
		nova->next = NULL;
		if (v->val == A)  // v->B
			nova->vrchol = vytvor(B, uzav);
		else 
			nova->vrchol = vytvor(A, uzav);
		if (v->hrana == NULL) // Bez hran			
			v->hrana = nova;
		else {
			Hrana *h = v->hrana;
			while (h != NULL) {
				if (h->next == NULL) {
					h->next = nova;
					break;
				}
				h = h->next;
			}
		}
}
 
int uzaver(Vrchol *v) {
	int pom = 0;
	if (v->hrana == NULL) return v->uzav;
	else 
 	{
 		Hrana *h = v->hrana;
 		while (h != NULL) {
 			pom += uzaver(h->vrchol); 			
 			h = h->next;
 		}
 	}	
	return pom;
}
 
int main()
{
 
	int n, val, A, B;
	while (scanf("%d %d", &n, &val) > 0) {
		Vrchol *v = vytvor(val, -1);
		while ((n-1) > 0) {
			scanf("%d %d %d", &A, &B, &val);
			//printf("%d\n", hladaj(v, A, B)->val);
			pridaj(hladaj(v, A, B), A, B, val);
			n--;
		}
		printf("%d\n", uzaver(v));
		free(v);
	}	
 
 
	return 0;
}