class Solution {
public:
    int mps[256],mpt[256];
    bool isIsomorphic(string s, string t) {
        memset(mps,-1,sizeof mps);
        memset(mpt,-1,sizeof mpt);
        for(int i = 0;i < s.size(); i++){
            if(mps[s[i] + 128]!=mpt[t[i] + 128])return false;
            mps[s[i] + 128] = mpt[t[i] + 128] = i;
        }
        return true;
    }
};

class Solution {
public:
    ListNode* reverseList(ListNode* head) {
        ListNode* pre = NULL;
        ListNode* nw = head;
        while(nw){
            ListNode* tmp = nw->next;
            nw->next = pre;
            pre = nw;
            nw = tmp;
        }
        return pre;
    }
};