[LeetCode] Isomorphic Strings, leetcodeisomorphic

[LeetCode] Isomorphic Strings, leetcodeisomorphic

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", Returntrue.
Given"foo","bar", Returnfalse.
Given"paper","title", Returntrue.

Note:
You may assume both s and t have the same length.

Solutions

Create two tables:
① Character ing table from string s to string t. Because the maximum letter is 122, the size of the ing table is 123. In the ing table, the key value is a character in s and the value is a character at the corresponding position in t.
② The isUsed table indicates whether the character t has been used as the value of a character in s.

Implementation Code

#include <iostream>using namespace std;//Runtime:12msclass Solution {public:    bool isIsomorphic(string s, string t) {        int len = s.size();        unsigned char map[123] = {0};        bool isUsed[123] = {0};        for (int i = 0; i < s.size(); i++)        {            if (map[s[i]] == 0)            {                if (!isUsed[t[i]])                {                    map[s[i]] = t[i];                    isUsed[t[i]] = true;                }                else                {                    return false;                }            }            else if (map[s[i]] != t[i])            {                return false;            }        }        return true;    }};int main(){    Solution s;    cout<<s.isIsomorphic("aba", "baa")<<endl;    cout<<s.isIsomorphic("egg", "add")<<endl;    cout<<s.isIsomorphic("foo", "bar")<<endl;    cout<<s.isIsomorphic("paper", "title")<<endl;}