# -*- coding: utf-8 -*-
"""
Created on Tue Oct 17 17:08:42 2017

@author: Karolis
"""

import numpy as np
import matplotlib.pyplot as plt

currentState = int(0)  #dabartine busena
state1 = 0          #kiek kartu grandine buvo 1-ame mazge
state2 = 0          #kiek kartu grandine buvo 2-ame mazge
state3 = 0          #kiek kartu grandine buvo 3-ame mazge

#funkcija pradiniam grandines mazgui nustatyti
def initState():
    x = np.random.random_sample()
    if x <= 1/3:
        currentState = 1
        global state1
        state1 += 1
    else:
        if x <= 2/3:
            currentState = 2
            global state2
            state2 += 1
        else:
            currentState = 3
            global state3
            state3 += 1
    return currentState

#funkcija nustatyti sekanciam grandines mazgui
def RNG(currentState):
    if currentState == 1 or currentState == 3:
        currentState = 2
        global state2
        state2 += 1
    else:
        if (np.random.random_sample() <= 0.5):
            currentState = 1
            global state1
            state1 += 1
        else:
            currentState = 3
            global state3
            state3 += 1
    return currentState


stateHistory = []       #masyvas, laikantis pirmu 50 busenu istorija
t = np.linspace(0, 49, 50)

currentState = initState()      #pradines busenos inicializacija

for i in range(50):             #pirmi 50 busenos pokyciu
    stateHistory.append(currentState)
    currentState = RNG(currentState)

for i in range(9949):
    currentState = RNG(currentState)

plt.plot(t, stateHistory, c='r')
print('Pirmos 50 busenu:')
print(stateHistory)
print('Pirmo, antro ir trecio mazgo apsilankymu skaiciai:')
print(state1, state2, state3)
pst1 = float(state1/10000)
pst2 = float(state2/10000)
pst3 = float(state3/10000)
print('Tikimybes:')
print(pst1, pst2, pst3)
print('Tikimybes is analiziniu skaiciavimu:')
print('0.25 0.5 0.25')