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Md Ariful Haque @mah-shamim

Counting Good Strings In Dynamic Programming

Dynamic Programming solution for "Count Ways To Build Good Strings" problem: calculate dp[i] as sum of dp[i-zero] and dp[i-one], with base case dp[0]=1. Return dp[low] + ... + dp[high] modulo 10^9+7.

2466. Count Ways To Build Good Strings
Difficulty: Medium
Topics: Dynamic Programming
Given the integers zero, one, low, and high, we can construct a string by starting with an empty string, and then at each step perform either of the following:

Append the character '0' zero times.
Append the character '1' one times.

This can be performed any number of times.
A good string is a string constructed by the above process having a length between low and high (inclusive).
Return the number of different good strings that can be constructed satisfying these properties. Since the answer can be large,...