~/lc-grind

Find the starting index of the first occurrence of a substring (`needle`) within another string (`haystack`), or return -1 if it's not found.

Master the zigzag pattern by learning how to rearrange a string row by row, as seen in the classic "PAYPALISHIRING" example.

Master the art of string manipulation by reversing the order of words while efficiently trimming all excess spaces using a two-pointer technique.

Find the longest starting substring shared by all strings in an array, or return an empty string if none exists.

Easily find the length of the final word in a string, even when trailing or multiple spaces are present.

Convert any integer between 1 and 3999 into its corresponding Roman numeral by strategically applying standard symbols and subtractive combinations like IV, IX, XL, and CM.

Efficiently convert a valid Roman numeral string to its integer equivalent by summing the values of its symbols while handling subtractive notation cases like "IV" for 4 or "XC" for 90.

Master multiple techniques—from two pointers to dynamic programming—to efficiently calculate how much rainwater a topographic elevation map can trap.

Minimize candy distribution while ensuring every child gets at least one and those with higher ratings than neighbors receive more, using a clever two-pass greedy approach.

Find the unique starting gas station index where a circular journey is possible by ensuring the total gas never dips below the cost at any point.