#n nodi
# 0,1,2,3,4,5,6...n-1
#tipologia = [B,P,B,P,P,P,P,B.......A]

def es1(G):
    n = size(G)

    for i in range(n):
        if tipologia[i] == "B":
            dist = Dijkstra(G,i)
            minimi = trova_3_minimi(dist)
            print(i,minimi)



def trova_3_minimi(dist):
    piscine = []

    for i in range(len(dist)):
        if tipologia[i] == 'P':
            piscine.append((i,dist[i]))

    piscine = mergesort(piscine)
    minimi = []
    if len(piscine) > 3:

        minimi.append(piscine[0][0])
        minimi.append(piscine[1][0])
        minimi.append(piscine[2][0])

    else:
        for i in range(len(piscine)):
            minimi.append(piscine[i][0])

    return minimi