205. Isomorphic Strings【LeetCode】

题目

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.
Example 1:
Input: s = “egg”, t = “add”
Output: true
Example 2:
Input: s = “foo”, t = “bar”
Output: false
Example 3:
Input: s = “paper”, t = “title”
Output: true

代码如下

class Solution {
public:
    bool isIsomorphic(string s, string t) {
        int len1 = s.length();
	int len2 = t.length();
	if(len1 != len2) return false; 
	vector<int> v1,v2;
	v1.push_back(0);
	v2.push_back(0);
	int cnt1 = 1,cnt2=1;
	for(int i = 1; i< s.size();i++)
	{
		if(s.find(s[i]) < i)
			v1.push_back(v1[s.find(s[i])]);
		else v1.push_back(cnt1++);
	}
	for(int i = 1; i< t.size();i++)
	{
		if(t.find(t[i]) < i)
			v2.push_back(v2[t.find(t[i])]);
		else v2.push_back(cnt2++);
	}
	for(int i = 0; i < v1.size();i++)
	{
		if(v1[i] != v2[i])
			return false;
	}
	return true;
    }
};