power = 0 value = 0 Loop though all of the letters of the string starting at the last position digit = numberString[i] - '0' value = value + digit * pow(10, power)
$a_nx^n + a_{n-1}x^{n-1} + ... + a_0$ $ = a_0 + a_1x^1 + a_2x^2 + ... + a_{n-2}x^{n-2} + a_{n-1}x^{n-1} + a_nx^n$ $ = a_0 + a_1x^1 + a_2x^2 + ... + a_{n-2}x^{n-2} + x^{n-1}(a_{n-1} + a_nx)$ $ = a_0 + a_1x^1 + a_2x^2 + ... + x^{n-2}(a_{n-2}+ x(a_{n-1} + a_nx))$ $ = a_0 + x(a_1 + x(a_2 + x(... + x(a_{n-1} + xa_n)...)$
a % b
or a modulus b?
7 % 4
= 3.