摘要:
1.题目描述 Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses. 给定n对括号,编写一个函数来生成格式正确的括号的所有组合。 2.题目分析 采用 阅读全文
摘要:
1.题目描述 Given an array S of n integers, are there elements a, b, c, and d in S such that a + b + c + d = target? Find all unique quadruplets in the arr 阅读全文