File22. Дан файл вещественных чисел. Создать файл целых чисел, содержащий номера всех локальных экстремумов исходного файла в порядке убывания (определение локального экстремума дано в задании File20).

Решение на Python 3:

import random

def GenerateNumbers(fname):
    N = random.randint(1,15)
    print("N = ",N)
    L = []
    x = random.randrange(1,10)
    L.append(x)
    for i in range(1,N):
        lst_rnd = list(range(1,10))
        lst_rnd.remove(x)
        x = random.choice(lst_rnd)
        L.append(x)
    print(L)
    try:
        f = open(fname, "w")
        try:
            for x in L:
                line = str(x)+"\n"
                f.write(line)
        finally:
            f.close()
    except IOError:
        print('Write error: ',fname)

def EmptyFile(fname):
    open(fname, 'w').close()
    
def Write2File(fname,value):
    try:
        f = open(fname, "a")
        try:
            s = str(value)+'\n'
            f.write(s)
        finally:
            f.close()
    except IOError:
        print('Write error: ',fname)

f_input = "file22_input.txt"
GenerateNumbers(f_input)

f_output = "file22_output.txt"
EmptyFile(f_output)

i = 0
try:
    with open(f_input,'r') as f_in:
        for line in f_in:
            i += 1
            x = int(line.strip())
            print(x)    
            if i == 1:
                x1 = x
                print("Local extremum:",x1,"; Extremum line:",1)
                Write2File(f_output,1)
            elif i == 2:
                x2 = x
            elif i == 3:
                x3 = x
                if (x1 < x2 and x2 > x3) or (x1 > x2 and x2 < x3):
                    print("Local extremum:",x2,"; Extremum line:",i-1)
                    Write2File(f_output,i)
            else:
                x1 = x2
                x2 = x3
                x3 = x
                #print(x1,x2,x3)
                if (x1 < x2 and x2 > x3) or (x1 > x2 and x2 < x3):
                    print("Local extremum:",x2,"; Extremum line:",i-1)
                    Write2File(f_output,i)

except IOError:
    print('Open error: ',f_source)
    
if i == 2:
    print("Local extremum:",x2,"; Extremum line:",2)
    Write2File(f_output,2)
elif i >= 3:
    print("Local extremum:",x3,"; Extremum line:",i)
    Write2File(f_output,i)