hdu 5349 MZL's simple problem

原题链接：http://acm.hdu.edu.cn/showproblem.php?pid=5349
直接模拟即可，我用的平衡树。。

#include<algorithm>#include<iostream>#include<cstdlib>#include<cstring>#include<cstdio>#include<vector>#include<map>using std::map;using std::min;using std::find;using std::pair;using std::vector;using std::multimap;#define all(c) (c).begin(), (c).end()#define iter(c) decltype((c).begin())#define cpresent(c, e) (find(all(c), (e)) != (c).end())#define rep(i, n) for (int i = 0; i < (int)(n); i++)#define tr(c, i) for (iter(c) i = (c).begin(); i != (c).end(); ++i)#define pb(e) push_back(e)#define mp(a, b) make_pair(a, b)const int N = 1 << 20;const int INF = 0x3f3f3f3f;inline int read() {    char c; int r;    while (((c = getchar()) < '0' || c > '9') && c ^ '-');    bool f = c == '-'; if (f) r = 0; else r = c - '0';    while ((c = getchar()) >= '0' && c <= '9') (r *= 10) += c - '0';    if (f) return -r; else return r;}struct Node {    int v, s, c;    Node *ch[2];    inline void set(int _v, int _s, Node *p) {        v = _v, s = c = _s;        ch[0] = ch[1] = p;    }    inline void push_up() {        s = ch[0]->s + ch[1]->s + c;    }    inline int cmp(int x) const {        return x == v ? -1 : x > v;    }};struct SizeBalanceTree {    int top;    Node *null, *root, *tail;    Node stack[N], *pool[N >> 1];    inline void init() {        top = 0;        tail = &stack[0];        null = tail++;        null->set(0, 0, NULL);        root = null;    }    inline Node *newNode(int v) {        Node *x = !top ? tail++ : pool[--top];        x->set(v, 1, null);        return x;    }    inline void rotate(Node *&x, int d) {        Node *k = x->ch[!d]; x->ch[!d] = k->ch[d], k->ch[d] = x;        k->s = x->s; x->push_up(); x = k;    }    inline void Maintain(Node *&x, int d) {        if (!x->s) return;        if (x->ch[d]->ch[d]->s > x->ch[!d]->s) rotate(x, !d);        else if (x->ch[d]->ch[!d]->s > x->ch[!d]->s) rotate(x->ch[d], d), rotate(x, !d);        else return;        Maintain(x, 0), Maintain(x, 1);    }    inline void insert(Node *&x, int v) {        if (!x->s) { x = newNode(v); return; }        x->s++;        int d = x->cmp(v);        if (-1 == d) { x->c++; return; }        insert(x->ch[d], v);        x->push_up();        Maintain(x, d);    }    inline void erase(Node *&x, int p) {        if (!x->s) return;        x->s--;        int d = x->cmp(p);        if (-1 == d) {            if (x->c > 1) { x->c--; return; }            else if (!x->ch[0]->s || !x->ch[1]->s) {                pool[top++] = x;                x = x->ch[0]->s ? x->ch[0] : x->ch[1];            } else {                Node *ret = x->ch[1];                for (; ret->ch[0]->s; ret = ret->ch[0]);                erase(x->ch[1], x->v = ret->v);            }        } else {            erase(x->ch[d], p);        }        if(x->s) x->push_up();    }    inline void insert(int v) {        insert(root, v);    }    inline void erase() {        erase(root, kth(1));    }    inline int kth(int k) {        Node *x = root;        for (int t = 0; x->s; ) {            t = x->ch[0]->s;            if (k <= t) x = x->ch[0];            else if (t + 1 <= k && k <= t + x->c) break;            else k -= t + x->c, x = x->ch[1];        }        return x->v;    }    inline void query() {        if(!root->s) { puts("0"); return; }        printf("%d\n", kth(root->s));    }}sbt;int main(){#ifdef LOCAL    freopen("in.txt", "r", stdin);    freopen("out.txt", "w+", stdout);#endif    sbt.init();    int n, v, op;    while(~scanf("%d", &n)) {        sbt.init();        rep(i, n) {            op = read();            if(1 == op) v = read(), sbt.insert(v);            if(2 == op) sbt.erase();            if(3 == op) sbt.query();        }    }    return 0;}