Solution of POJ 2001-Shortest Prefixes

See the problem  POJ 2001-Shortest Prefixes

    // Solution using "Trie"

    #include<iostream>
    #include<vector>
    #include<string>
    using namespace std;
    vector<string>vt;
    vector<string>::iterator it;

    long long i, k, sz, cur, last, x;
    string s;

    struct node{
        int next[26+1];
        int cnt;
    }ar[20109];

    void new_trie(int cur){
        for(int j=0; j<26; j++)ar[cur].next[j]=-1;
        ar[cur].cnt=1;
    }

    void insrt(){
        cur=0, sz=s.size();
        for(i=0; i<sz; i++){
            x=s[i]-'a';
            if(ar[cur].next[x]==-1){
                ar[cur].next[x]=last;
                new_trie(last++);
                cur=ar[cur].next[x];
            }
            else{
                cur=ar[cur].next[x];
                ar[cur].cnt++;
            }
        }
    }

    void fnd(){
        sz=s.size(), cur=0;
        for(i=0; i<sz; i++){
            x=s[i]-'a';
            cout<<s[i];
            cur=ar[cur].next[x];
            if(ar[cur].cnt==1) i=sz;
        }
    }

    int main()
    {
        new_trie(0);
        last=1;
        while(getline(cin, s)){
            if(s.size()==0) break;
            vt.push_back(s);
            insrt();
        }
        for(it=vt.begin(); it<vt.end(); it++){
            s=*it;
            cout<<s<<" ";
            fnd();
            cout<<endl;
        }
        return 0;
    }