205. isomorphic string

205. Isomorphic Strings

Given two strings s and t , Judge whether they are isomorphic .

If s The characters in can be replaced according to some mapping relationship t , So these two strings are isomorphic .

Every character that appears should be mapped to another character , Without changing the order of characters . Different characters cannot be mapped to the same character , The same character can only be mapped to the same character , Characters can be mapped to themselves .

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

bool isIsomorphic(char * s, char * t){
    
    int r[128];
    int rs[128];
    int i;
    for(i=0;i<128;i++){
    
        r[i]=-99;
        rs[i]=0;
    }
    for(i=0;s[i]!='\0';i++){
    
        int val=s[i]-t[i];
       
        if(r[s[i]]==-99){
    
            r[s[i]]=val;
            rs[t[i]]++;
            if(rs[t[i]]>1){
    
                return false;
            }
        }
        else{
    
            if(r[s[i]]!=val){
    
                return false;
            }
        }


    }
    return true;


}