Leetcode 3703. Remove K-Balanced Substrings

• Leetcode 3703. Remove K-Balanced Substrings
  • 1. 解题思路
  • 2. 代码实现

• 题目链接：3703. Remove K-Balanced Substrings

1. 解题思路

这一题思路上就是一个堆栈的思路，我们只需要将所有的括号进行聚合，然后统一进行进栈以及消除操作即可。

2. 代码实现

给出python代码实现如下：

class Solution:
    def removeSubstring(self, s: str, k: int) -> str:
        stack = []
        prev, cnt = "(", 0
        
        def push(stack, ch, cnt):
            if len(stack) == 0:
                stack.append([ch, cnt])
            elif ch == stack[-1][0]:
                stack[-1] = [ch, stack[-1][1] + cnt]
            elif ch == "(":
                stack.append([ch, cnt])
            else:
                while stack and cnt >= k and stack[-1][1] >= k:
                    stack[-1][1] -= k
                    cnt -= k
                    if stack[-1][-1] == 0:
                        stack.pop()
                        if stack and stack[-1][0] == ch:
                            cnt += stack.pop()[1]
                if cnt > 0:
                    if len(stack) == 0 or stack[-1][0] != ch:
                        stack.append([ch, cnt])
                    else:
                        stack[-1] = [ch, stack[-1][1] + cnt]
            return

        for ch in s:
            if ch == prev:
                cnt += 1
                continue
            if cnt != 0:
                push(stack, prev, cnt)
            prev, cnt = ch, 1
        push(stack, ch, cnt)
        ans = ""
        for ch, cnt in stack:
            ans += ch * cnt
        return ans

提交代码评测得到：耗时255ms，占用内存22.75MB。