Published onMay 9, 2022[LeetCode 150] Evaluate Reverse Polish NotationStackEvaluate the value of an arithmetic expression in Reverse Polish Notation.
Published onFebruary 13, 2022[LeetCode 84] Largest Rectangle in HistogramStackGiven an array of integers `heights` representing the histogram's bar height where the width of each bar is `1`, return the area of the largest rectangle in the histogram.
Published onNovember 30, 2021[LeetCode 20] Valid ParenthesesStackGiven a string s containing just the characters '(', ')', '{', '}', '[' and ']', determine if the input string is valid.