P3369 [template] general balanced tree (splay)

splay support queries

1. The first big k

2. Who was the first big k

3. The number of precursors

4. The number of subsequent

5. Add Remove

 

#include <. bits / STDC ++ H>
 the using  namespace STD; 

int RT, CNT;
 int CH [ 100005 ] [ 2 ];     // left son 
int FA [ 100005 ];        // parent node 
int SZ [ 100005 ];        // Word tree and 
int CN [ 100005 ];        // current point appears many times 
int Val [ 100005 ];       // current point weights 

void Clear ( int X) { 
    SZ [X] = FA [X] = CH [X] [ 0 ] = CH [X] [1] = cn[x] = val[x] = 0;
}

bool ws(int x) {  //which son
    return ch[fa[x]][1] == x;  // 右儿子1 左儿子0
}

void update(int x) {
    if(x) {
        sz[x] = cn[x];
        if(ch[x][0]) sz[x] += sz[ch[x][0]];
        if(ch[x][1]) sz[x] += sz[ch[x][1]];
    }
}

void setfa(int x, int f, int d) {
    if(x != 0) fa[x] = f;
    if(f != 0) ch[f][d] = x;
}

void rot(int x) {
    int f = fa[x]; int ff = fa[f]; int s1 = ws(x); int s2 = ws(f);
    int p = ch[x][s1 ^ 1];
    setfa(p, f, s1);
    setfa(f, x, s1 ^ 1);
    setfa(x, ff, s2);
    update(f);
    update(x);
}

void splay(int x) {
    for(; fa[x]; rot(x))
        if(fa[fa[x]] && ws(x) == ws(fa[x])) rot(fa[x]);
    rt = x;
}

void inser(int x) {
    if(rt == 0) {
        cnt++; ch[cnt][0] = ch[cnt][1] = fa[cnt] = 0;
        val[cnt] = x;
        cn[cnt] = 1;
        sz[cnt] = 1;
        rt = cnt;
        return;
    }

    int now = rt, f = 0;
    while(1) {
        if(val[now] == x) {
            cn[now]++; update(now); update(f);
            splay(now);
            break;
        }

        f = now;
        now = ch[now][val[now] < x];
        if(now == 0) {
            cnt++;
            val[cnt] = x;
            cn[cnt] = sz[cnt] = 1;
            fa[cnt] =F; 
            CH [F] [Val [F] <X] = CNT; 
            CH [CNT] [ . 1 ] = CH [CNT] [ 0 ] = 0 ; 
            Update (F); 
            The splay (CNT); 
            BREAK ; 
        } 
    } 
} 

int the Find ( int the X-) {      // query rank = how much smaller than his 1 + 
    int now = RT, RES = 0 ;
     the while ( 1 ) {
         IF (the X-<Val [now]) now = CH [now] [ 0 ]; // left 
        the else {
             IF (CH [now] [0]) res += sz[ch[now][0]];
            if(x == val[now]) {
                splay(now);
                return res + 1;
            }
            res += cn[now];
            now = ch[now][1];
        }
    }
}

int ffind(int x) {  //查询排名为x的数
    int now = rt, res = 0;
    while(1) {
        if(ch[now][0] && x <= res + sz[ch[now][0]]) now = ch[now][0];
        else {
            if(ch[now][0]) res += sz[ch[now][0]];
            res += cn[now];

            if(res >= x) return val[now];
            now = ch[now][1];
        }
    }
}

int pre() {  //前驱
    int now = ch[rt][0];
    while(ch[now][1]) now = ch[now][1];
    return now;
}

int nex() {
    int now = ch[rt][1];
    while(ch[now][0]) now = ch[now][0];
    return now;
}

void del(int x) {
    int no = find(x);
    if(cn[rt] > 1) {
        cn[rt]--;
        return;
    }

    if(!ch[rt][0] && !ch[rt][1]) {  //没孩子
        clear(rt);
        rt = 0;
        return;
    }
    if(!ch[rt][0]) {
        int oldrt = rt;
        rt = ch[rt][1]; fa[rt] = 0;
        clear(oldrt);
        return;
    }

    if(!ch[rt][1]) {
        int oldrt = rt;
        rt = ch[rt][0]; fa[rt] = 0;
        clear(oldrt);
        return;
    }
    // two children
    int lrt = pre();
    int oldrt = rt;
    splay(lrt);
    fa[ch[oldrt][1]] = lrt;
    ch[rt][1] = ch[oldrt][1];
    clear(oldrt);
    update(rt);
}

int main() {
    rt = 0;
    cnt = 0;
    int T;
    scanf("%d", &T);
    while(T--) {
        int opt, x;
        scanf("%d%d", &opt, &x);
        switch(opt) {
            case 1: inser(x); break;
            case 2: del(x); break;
            case 3: printf("%d\n", find(x)); break;
            case 4: printf("%d\n", ffind(x)); break;
            case 5: inser(x), printf("%d\n", val[pre()]), del(x); break;
            case 6: inser(x), printf("%d\n", val[nex()]), del(x); break;
        }
    }
    return 0;
}

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