Project Euler Problem40

Problem 40

An irrational decimal fraction is created by concatenating the positive integers:

0.123456789101112131415161718192021...

It can be seen that the 12^th digit of the fractional part is 1.

If d_n represents the n^th digit of the fractional part, find the value of the following expression.

d₁ × d₁₀ × d₁₀₀ × d₁₀₀₀ × d₁₀₀₀₀ × d₁₀₀₀₀₀ × d_1000000

#求0.12345678910...这个小数的第1位，第10位，第100位...第1百万位的数之积。

string = '0'
i = 1
while i < 200000:
    string += str(i)
    i += 1
product = 1
for i in range(0,7):
    ex = 10**i
    product *= int(string[ex])

print(product)