====== 3. Cykly a funkce ======

===== 1. příklad =====

<code python>
# program na aproximaci Ludolfova cisla metodou Monte Carlo
import random
import math

m = 0   # cisla vne jednotkove kruznice
n = 0   # cisla uvnitr jednotkove kruznice

for i in range(1000000):
    x = random.random()
    y = random.random()
    z = math.sqrt(x*x + y*y)

    if z > 1:
        m += 1
    else:
        n += 1

piq = n/(n+m)

print("pi = %.6f" % (piq*4))
</code>

===== 2. příklad =====
<code python>
# program pro kresleni geometrickych tvaru
for a in range(1,6):
    for b in range(a):
        print('*', end='')
    print()

print()

for a in range(5):
    for b in range(5-a):
        print('*', end='')
    print()

print()

for a in range(1,6):
    for b in range(1,6-a):
        print(' ', end='')
    for b in range(a):
        print('*', end='')
    print()
    
print()

# poznamka k funkci range

for i in range(1,10,2):
    print(i, end=' ')
print()

for i in range(10, 1, -2):
    print(i, end=' ')
print()
</code>

===== 3. příklad =====
<code python>
# diagonaly
for i in range(100):
    if (i % 11 == 0):
        print (str(i).rjust(3), end='')
    elif (i % 9 == 0):
        print (str(i).rjust(3), end='')
    else:
        print ('   ', end='')
    if (i % 10)==9: print()
</code>

===== 4. příklad =====
<code python>
mons = ['Leden', 'Unor', 'Brezen', 'Duben']
days = ['Po', 'Ut', 'St', 'Ct', 'Pa', 'So', 'Ne']
nums = [31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31]

def calendar (mesic, den):
    konec = 0
    print(" " + mons[mesic-1])
    # tisk nazvu dnu v tydnu
    for i in range(7):
        print(days[i].rjust(3), end='')
    # odradkovani
    print()
    # tisk cisel dnu v mesici
    for i in range(1, nums[mesic-1]+den):
        konec += 1
        if i < den:
            print('   ', end='')
        else:
            print(str(i-den+1).rjust(3), end='')
        if i % 7 == 0:
            print()
            konec = 0
    print("\n")
    return konec

k = calendar (1, 2)
k = calendar (2, k+1)
</code>