File20. Файли ададҳои ҳақиқӣ дода шудааст. Миқдори умумии экстремумҳои он (яъне минимумҳои локалӣ ва максимумҳои локалӣ) ёфта шавад.

Таърифи минимуми локалӣ ва максимуми локалӣ дар масъалаҳои FILE18 ва FILE19 оварда шудаанд.

Решение на Python 3:

import random

def GenerateLine(fname):
    N = random.randrange(1,10)
    print("N = ",N)
    #N = 2
    #line = "1, 5, 5, 5, 4, 4, 5"
    try:
        f = open(fname, "w")
        try:
            for i in range(N):
                line = str(random.randint(1,4))+"\n"
                f.write(line)
        finally:
            f.close()
    except IOError:
        print('Write error: ',fname)

f_input = "file20_input.txt"
#GenerateLine(f_input)

unique_num = 0
extr_num = 2
try:
    with open(f_input,'r') as f_in:
        for line in f_in:
            x = int(line.strip())
            print(x)

            if unique_num > 0 and x == x_prev:
                #print(" : skipped")
                continue
            
            x_prev = x
            unique_num += 1
            if unique_num == 1:
                x1 = x
            elif unique_num == 2:
                x2 = x
            elif unique_num == 3:
                x3 = x
                #print("hello: {0},{1},{2}".format(x1,x2,x3))
                if (x1 < x2 and x2 > x3) or (x1 > x2 and x2 < x3):
                    extr_num += 1
            else:
                x1 = x2
                x2 = x3
                x3 = x
                if (x1 < x2 and x2 > x3) or (x1 > x2 and x2 < x3):
                    extr_num += 1
            #print(":",extr_num,":",unique_num)

except IOError:
    print('Open error: ',f_source)

print("unique_num: ",unique_num)

if unique_num == 1:
    extr_num = 1
elif unique_num == 2:
    extr_num = 2
    
print("Number of local extremums:",extr_num)