1544. Make The String Great 链接到标题 使用栈来记录最终结果，如果栈顶和当前字符相同，那么出栈，否则入栈。class Solution: def makeGood(self, s: str) -> str: stack = [] for i in s: if stack and ((ord(stack[-1])-32) == ord(i) or (ord(stack[-1])+32) == ord(i)): stack.pop() else: stack.append(i) return ''.join(stack) 1545. Find Kth Bit in Nt……