# 档案日期2018的7

## LeetCode Weekly Contest 72解题报告 作者是 在线疯狂 发布于 2018年2月18日 在 LeetCode.

LeetCode Weekly Contest 72是LeetCode举办的第七十六场正式周赛，共4道题目，比赛时长1.5小时。

LeetCode 784. Letter Case Permutation

LeetCode 785. Is Graph Bipartite?

LeetCode 787. Cheapest Flights Within K Stops

LeetCode 786. K-th Smallest Prime Fraction

## 题目描述：

LeetCode 786. K-th Smallest Prime Fraction

A sorted list A contains 1, plus some number of primes.  Then, for every p < q in the list, we consider the fraction p/q.

What is the K-th smallest ...

## 题目描述：

LeetCode 787. Cheapest Flights Within K Stops

There are n cities connected by m flights. Each fight starts from city u and arrives at v with a price w.

Now given all the cities and fights, together with starting ...

## 题目描述：

LeetCode 785. Is Graph Bipartite?

Given a graph, return true if and only if it is bipartite.

Recall that a graph is bipartite if we can split it's set of nodes into two independent subsets A and B such that ...

## 题目描述：

LeetCode 784. Letter Case Permutation

Given a string S, we can transform every letter individually to be lowercase or uppercase to create another string.  Return a list of all possible strings we could create.

Examples:
Input: S = "a1b2"
Output ...