UVA 1525 Falling Leaves

 #include <cmath>

 #include <ctime>

 #include <iostream>

 #include <string>

 #include <vector>

 #include <cstdio>

 #include <cstdlib>

 #include <cstring>

 #include <queue>

 #include <map>

 #include <set>

 #include <algorithm>

 #include <cctype>

 #include <stack>

 #include <deque>

 #include <list>

 #include <sstream>

 #include <cassert>

 using namespace std;

 #define INIT() ios::sync_with_stdio(false);cin.tie(0);cout.tie(0);

 #define Rep(i,n) for (int i = 0; i < (int)(n); ++i)

 #define For(i,s,t) for (int i = (int)(s); i <= (int)(t); ++i)

 #define rFor(i,t,s) for (int i = (int)(t); i >= (int)(s); --i)

 #define ForLL(i, s, t) for (LL i = LL(s); i <= LL(t); ++i)

 #define rForLL(i, t, s) for (LL i = LL(t); i >= LL(s); --i)

 #define foreach(i,c) for (__typeof(c.begin()) i = c.begin(); i != c.end(); ++i)

 #define rforeach(i,c) for (__typeof(c.rbegin()) i = c.rbegin(); i != c.rend(); ++i)

 #define pr(x) cout << #x << " = " << x << "  "

 #define prln(x) cout << #x << " = " << x << endl

 #define LOWBIT(x) ((x)&(-x))

 #define ALL(x) x.begin(),x.end()

 #define INS(x) inserter(x,x.begin())

 #define UNIQUE(x) x.erase(unique(x.begin(), x.end()), x.end())

 #define REMOVE(x, c) x.erase(remove(x.begin(), x.end(), c), x.end()); // 删去 x 中所有 c

 #define TOLOWER(x) transform(x.begin(), x.end(), x.begin(),::tolower);

 #define TOUPPER(x) transform(x.begin(), x.end(), x.begin(),::toupper);

 #define ms0(a) memset(a,0,sizeof(a))

 #define msI(a) memset(a,0x3f,sizeof(a))

 #define msM(a) memset(a,-1,sizeof(a))

 #define MP make_pair

 #define PB push_back

 #define ft first

 #define sd second

 template<typename T1, typename T2>

 istream &operator>>(istream &in, pair<T1, T2> &p) {

     in >> p.first >> p.second;

     return in;

 }

 template<typename T>

 istream &operator>>(istream &in, vector<T> &v) {

     for (auto &x: v)

         in >> x;

     return in;

 }

 template<typename T>

 ostream &operator<<(ostream &out, vector<T> &v) {

     Rep(i, v.size()) out << v[i] << " \n"[i == v.size()];

     return out;

 }

 template<typename T1, typename T2>

 ostream &operator<<(ostream &out, const std::pair<T1, T2> &p) {

     out << "[" << p.first << ", " << p.second << "]" << "\n";

     return out;

 }

 inline int gc(){

     static const int BUF = 1e7;

     static char buf[BUF], *bg = buf + BUF, *ed = bg;

     if(bg == ed) fread(bg = buf, , BUF, stdin);

     return *bg++;

 } 

 inline int ri(){

     int x = , f = , c = gc();

     for(; c<||c>; f = c=='-'?-:f, c=gc());

     for(; c>&&c<; x = x* + c - , c=gc());

     return x*f;

 }

 template<class T>

 inline string toString(T x) {

     ostringstream sout;

     sout << x;

     return sout.str();

 }

 inline int toInt(string s) {

     int v;

     istringstream sin(s);

     sin >> v;

     return v;

 }

 //min <= aim <= max

 template<typename T>

 inline bool BETWEEN(const T aim, const T min, const T max) {

     return min <= aim && aim <= max;

 }

 typedef long long LL;

 typedef unsigned long long uLL;

 typedef vector< int > VI;

 typedef vector< bool > VB;

 typedef vector< char > VC;

 typedef vector< double > VD;

 typedef vector< string > VS;

 typedef vector< LL > VL;

 typedef vector< VI > VVI;

 typedef vector< VB > VVB;

 typedef vector< VS > VVS;

 typedef vector< VL > VVL;

 typedef vector< VVI > VVVI;

 typedef vector< VVL > VVVL;

 typedef pair< int, int > PII;

 typedef pair< LL, LL > PLL;

 typedef pair< int, string > PIS;

 typedef pair< string, int > PSI;

 typedef pair< string, string > PSS;

 typedef pair< double, double > PDD;

 typedef vector< PII > VPII;

 typedef vector< PLL > VPLL;

 typedef vector< VPII > VVPII;

 typedef vector< VPLL > VVPLL;

 typedef vector< VS > VVS;

 typedef map< int, int > MII;

 //typedef unordered_map< int, int > uMII;

 typedef map< LL, LL > MLL;

 typedef map< string, int > MSI;

 typedef map< int, string > MIS;

 typedef set< int > SI;

 typedef stack< int > SKI;

 typedef queue< int > QI;

 typedef priority_queue< int > PQIMax;

 typedef priority_queue< int, VI, greater< int > > PQIMin;

 const double EPS = 1e-;

 const LL inf = 0x7fffffff;

 const LL infLL = 0x7fffffffffffffffLL;

 const LL mod = 1e9 + ;

 const int maxN = 1e3 + ;

 const LL ONE = ;

 const LL evenBits = 0xaaaaaaaaaaaaaaaa;

 const LL oddBits = 0x5555555555555555;

 struct BSTNode {

     char var;

     int lc, rc, cnt;

     BSTNode() {}

     BSTNode(char x) {

         lc = rc = ;

         var = x;

         cnt = ;

     }

 };

 int N;

 VS leaf;

 string tmp;

 vector< BSTNode > bst;

 void insertBSTNode(char x, int rt) {

     if(x < bst[rt].var) {

         if(bst[rt].lc) insertBSTNode(x, bst[rt].lc);

         else {

             bst[rt].lc = bst.size();

             bst.PB(BSTNode(x));

         }

     }

     else if(x > bst[rt].var) {

         if(bst[rt].rc) insertBSTNode(x, bst[rt].rc);

         else {

             bst[rt].rc = bst.size();

             bst.PB(BSTNode(x));

         }

     }

     //else ++bst[rt].cnt;

 }

 void preOrder(int rt) {

     cout << bst[rt].var;

     if(bst[rt].lc) preOrder(bst[rt].lc);

     if(bst[rt].rc) preOrder(bst[rt].rc);

 }

 int main(){

     //freopen("MyOutput.txt","w",stdout);

     //freopen("input.txt","r",stdin);

     INIT();

     while(tmp != "$") {

         leaf.clear();

         bst.clear();

         bst.PB(BSTNode()); // 0 号节点设为空节点 

         while(cin >> tmp && tmp != "*" && tmp != "$") leaf.PB(tmp);

         bst.PB(BSTNode(leaf.back()[]));

         rFor(i, leaf.size() - , ) Rep(j, leaf[i].size()) insertBSTNode(leaf[i][j], );

         preOrder();

         cout << endl;

     }

     return ;

 }