【LeetCode】205. Isomorphic Strings

问题描述

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.

字符串同型分析，即需要实现s中每个字符对应着t的某个字符，并且只有一个对应；t中的每个字符对应着s中的某个字符，也只有一个对应。双向的一对一关系。

代码

class Solution {
public:
    bool isIsomorphic(string s, string t) {
    	if(s.length()!=t.length()) return false;
    	char c1[256]={
	    	'\0'
	    };
    	char c2[256]={
	    	'\0'
	    };
        for(int i=0;i<s.length();i++) {
        	if(c1[s[i]]=='\0') {
	        	c1[s[i]] = t[i];
	        } else {
        		if(c1[s[i]]!=t[i]) {
		        	return false;
		        }
        	}
	        if(c2[t[i]]=='\0') {
        		c2[t[i]] = s[i];
        	} else {
	        	if(c2[t[i]]!=s[i]) {
	        		return false;
	        	}
	        }
        }
        return true;
    }
};