Tag: C++ stack

Given the root of a binary tree, each node has a value from 0 to 25 representing the letters ‘a’ to ‘z’: a value of 0 represents ‘a’, a …

Given two sequences pushed and popped with distinct values, return true if and only if this could have been the result of a sequence of push and pop operations …

You are given a string s that consists of lower case English letters and brackets. Reverse the strings in each pair of matching parentheses, starting from the innermost one. …