萌新的splay求职

#include<bits/stdc++.h>
#define rep(i,j,k) for(register int i(j);i<=k;++i)
using namespace std;
const int N = 100079;
const int inf = 0x7fffffff;
int n, m;
int a[N];
#define lc son[x][0]
#define rc son[x][1]
struct BST
{
    int tot, size[N], son[N][2];
    int fa[N], rev[N],val[N];
    int root;
    inline void pushup(int x)
    {
        size[x] = size[lc] + size[rc] + 1;
    }
    inline int relation(int x)
    {
        return son[fa[x]][1] == x;
    }
    inline void pushdown(int x)
    {
        if(!rev[x]) return ;
        rev[lc] ^= 1;
        rev[rc] ^ 1;
        swap(fa[lc],fa[rc]);
        swap(size[lc],size[rc]);
        swap(val[lc],val[rc]);
        swap(rev[lc],rev[rc]);
        swap(son[1][lc],son[1][rc]);
        swap(son[0][lc],son[0][rc]);
        rev[x] = 0;
    }

    inline void connect(int x, int f, int next)
    {
        fa[x] = f;
        son[f][next] = x;
    }
    inline void rotate(int x)
    {
        int y(fa[x]), r = fa[y];
        pushdown(y);pushdown(r);
        int dy = relation(y), dx = relation(x);
        int b = son[x][dx ^ 1];

        connect(b, y, dx);
        connect(y, x, dx ^ 1);
        connect(x, r, dy);
        pushup(y);
        pushup(x);
    }
    inline void splay(int x, int to)
    {
        int ed = fa[to];
        while(fa[x] != ed)
        {
            int y = fa[x];
            if(fa[y] == ed) rotate(x);
            else if(relation(x) == relation(y)) rotate(y), rotate(x);
            else rotate(x), rotate(x);
        }
    }
    inline int create(int key, int f)
    {
        tot++;
        val[tot]=key;
        size[tot] = 1;
        son[tot][0] = son[tot][1] = 0;
        fa[tot] = f;
        return tot;
    }
    inline int build(int L, int R, int f)
    {
        if(L > R) return 0;
        int mid((L + R) >> 1);
        int p = create(a[mid], f);
        son[p][0] = build(L, mid - 1, p);
        son[p][1] = build(mid + 1, R, p);
        pushup(mid);
        return p;
    }
    inline int findkey(int x, int k)
    {   
        pushdown(x);
        if(size[lc] + 1 == k) return x;
        if(k < size[lc] + 1) return findkey(lc, k);
        if(k > size[lc] + 1) return findkey(rc, k - 1 - size[lc]);
    }
    inline void rever(int x, int y)
    {
        int L=x-1,R=y+1;
        L=findkey(root,L),R=findkey(root,R);
        splay(L, root);
        splay(R, son[root][1]);
        R=son[root][1];
        rev[son[R][0]] ^= 1;
    }
    inline void print(int x)
    {
        pushdown(x);
        if(lc) print(lc);
        if(val[x]!=inf&&val[x]!=-inf) cout << val[x] << ' ';
        if(rc) print(rc);
    }
} S;
int main()
{
    cin >> n >> m;
    a[1] = -inf;
    a[n + 2] = inf;
    rep(i, 1, n) a[i + 1] = i;
    S.root=S.build(1, n + 2, 0);
    rep(i, 1, m)
    {
        int l, r;
        cin >> l >> r;
        S.rever(l + 1, r + 1);
    }
    S.print(S.root);
    return 0;
}

样例过不了，