[leetcode]205. Isomorphic Strings

题目链接：https://leetcode.com/problems/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.

class Solution {
public:
string transferStr(string s){
char table[128] = {0};
char tmp = '0';
for (int i=0; i<s.length(); i++) {
char c = s.at(i);
if (table[c] == 0) {
table[c] = tmp++;
}
s[i] = table[c];
}
return s;
}
bool isIsomorphic(string s, string t) {

if (s.length() != t.length()) {
return false;
}
if (transferStr(s) == transferStr(t)) {
return true;
}
return false;
}
};