Python 刷Leetcode题库，顺带学英语单词（46）

Isomorphic Strings

Given two strings s and t, determine if they are isomorphic.

Two strings are isomorphic if the characters in s can be replaced to get t.    [#205]

All occurrences of a character must be replaced with another character while preserving the order of characters. No two characters may map to the same character but a character may map to itself.

   Examples:

Input: s = "egg", t = "add"
    Output: true
    Input: s = "foo", t = "bar"
    Output: false
    Input: s = "paper", t = "title"
    Output: true

Note:

You may assume both s and t have the same length.

Word Pattern

Given a pattern and a string str, find if str follows the same pattern.    [#290]

Here follow means a full match, such that there is a bijection between a letter in pattern and a non-empty word in str.

   Examples:

Input: pattern = "abba", str = "dog cat cat dog"
    Output: true
    Input:pattern = "abba", str = "dog cat cat fish"
    Output: false
    Input: pattern = "aaaa", str = "dog cat cat dog"
    Output: false
    Input: pattern = "abba", str = "dog dog dog dog"
    Output: false

Note:

You may assume pattern contains only lowercase letters, and str contains lowercase letters separated by a single space.

题意：给定一个模式串，判断字符串和给定模式串是否为相同模式。