[LeetCode] Isomorphic Strings - 字符串操作:数组计数字符个数问题

bool isIsomorphic(char* s, char* t) {
    int ls,lt;     //字符串长度
    int i,j;
    int nums[256]={0};
    int numt[256]={0};
    
    ls = strlen(s);
    lt = strlen(t);
    if(ls!=lt) return false;
    for(i=0; i<ls; i++) {
        //初值为0
        if(nums[s[i]]==0) {
            if(numt[t[i]]==0) {
                nums[s[i]] = t[i];
                numt[t[i]] = s[i];
            }
            else {
                return false;
            }
        }
        else {
            if(nums[s[i]]!=t[i]) {
                return false;
            }
        }
    }
    return true;
}

class Solution {
public:
    bool isIsomorphic(string s, string t) {
        if (s.length() != t.length()) return false;
        map<char, char> mp;
        for (int i = 0; i < s.length(); ++i) {
            if (mp.find(s[i]) == mp.end()) mp[s[i]] = t[i];
            else if (mp[s[i]] != t[i]) return false;
        }
        mp.clear();
        for (int i = 0; i < s.length(); ++i) {
            if (mp.find(t[i]) == mp.end()) mp[t[i]] = s[i];
            else if (mp[t[i]] != s[i]) return false;
        }
        return true;
    }
};