29
04/2015
[LeetCode] Isomorphic Strings
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.
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.
解题思路：
这道题是判断两个单词是否同构。这里的同构的意思是，对于例子egg和add，若存在一个映射，e->a，g->d，单词egg和add同构。注意，不可以多个字符映射到同一个字符中去，比如aa和ab。因此要有两个hash表来记录。由于是字符，不会超过256个，因此可以用数组来记录这种映射。
class Solution {
public:
bool isIsomorphic(string s, string t) {
int len1=s.length();
int len2=t.length();
if(len1!=len2){
return false;
}
char charMap[256];
char charMap1[256];
memset(charMap, 0, sizeof(char)*256);
memset(charMap1, 0, sizeof(char)*256);
for(int i=0; i<len1; i++){
if(charMap[s[i]]==0){
charMap[s[i]] = t[i];
}else if(charMap[s[i]]!=t[i]){
return false;
}
if(charMap1[t[i]]==0){
charMap1[t[i]] = s[i];
}else if(charMap1[t[i]]!=s[i]){
return false;
}
}
return true;
}
};转载请注明：康瑞部落 » [LeetCode] Isomorphic Strings
0 条评论