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Formatted question description: https://leetcode.ca/all/2489.html

# 2489. Number of Substrings With Fixed Ratio

## Description

You are given a binary string `s`

, and two integers `num1`

and `num2`

. `num1`

and `num2`

are coprime numbers.

A **ratio substring** is a substring of s where the ratio between the number of `0`

's and the number of `1`

's in the substring is exactly `num1 : num2`

.

- For example, if
`num1 = 2`

and`num2 = 3`

, then`"01011"`

and`"1110000111"`

are ratio substrings, while`"11000"`

is not.

Return *the number of non-empty ratio substrings of *

`s`

.**Note** that:

- A
**substring**is a contiguous sequence of characters within a string. - Two values
`x`

and`y`

are**coprime**if`gcd(x, y) == 1`

where`gcd(x, y)`

is the greatest common divisor of`x`

and`y`

.

**Example 1:**

Input:s = "0110011", num1 = 1, num2 = 2Output:4Explanation:There exist 4 non-empty ratio substrings. - The substring s[0..2]: "0110011". It contains one 0 and two 1's. The ratio is 1 : 2. - The substring s[1..4]: "0110011". It contains one 0 and two 1's. The ratio is 1 : 2. - The substring s[4..6]: "0110011". It contains one 0 and two 1's. The ratio is 1 : 2. - The substring s[1..6]: "0110011". It contains two 0's and four 1's. The ratio is 2 : 4 == 1 : 2. It can be shown that there are no more ratio substrings.

**Example 2:**

Input:s = "10101", num1 = 3, num2 = 1Output:0Explanation:There is no ratio substrings of s. We return 0.

**Constraints:**

`1 <= s.length <= 10`

^{5}`1 <= num1, num2 <= s.length`

`num1`

and`num2`

are coprime integers.