leetCode 205. Isomorphic Strings 哈希 字符串相似

205. Isomorphic Strings 字符串相似

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.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.For example,
Given

"egg"

,

"add"

, return true.Given

"foo"

,

"bar"

, return false.Given

"paper"

,

"title"

, return true.Note:
You may assume both s and t have the same length.题目大意：
判断两个字符串是否相似。
思路：
使用双map来进行比较。map键为字符串元素，值为字符上一次出现的位置。
代码如下：

class Solution {
public:
bool isIsomorphic(string s, string t) {
if(s.size() != t.size())
return false;
unordered_map<char,int> maps;
unordered_map<char,int> mapt;
for(int i = 0;i < s.size();i++)
{
if(maps.find(s[i]) == maps.end() && mapt.find(t[i]) == mapt.end())
{
maps.insert(pair<char,int>(s[i],i));
mapt.insert(pair<char,int>(t[i],i));
}
else if(maps.find(s[i]) != maps.end() && mapt.find(t[i]) != mapt.end())
{
if(maps[s[i]] != mapt[t[i]])
return false;
else
{
maps[s[i]] = i;
mapt[t[i]] = i;
}
}
else
return false;
}
return true;
}
};

2016-08-13 17:15:21