摘要:
Given four lists A, B, C, D of integer values, compute how many tuples (i, j, k, l) there are such that A[i] + B[j] + C[k] + D[l] is zero. To make pro 阅读全文
摘要:
You are given two linked lists representing two non-negative numbers. The most significant digit comes first and each of their nodes contain a single 阅读全文
摘要:
Given n pairs of parentheses, write a function to generate all combinations of well-formed parentheses. For example, given n = 3, a solution set is: c 阅读全文