萌新求助

文艺平衡树一开始不插入最大值和最小值的操作是否影响正确性?为什么?

代码:如果不插入2147483647 -2147483647就过不了

#include <bits/stdc++.h>
#define maxn 500005
using namespace std;
int ch[maxn][2], fa[maxn], val[maxn], cnt[maxn], tot, n, sz[maxn], rt, ver[maxn], m;
void maintain(int x) {
    sz[x] = sz[ch[x][0]] + sz[ch[x][1]] + cnt[x];
}
bool get(int x) {
    return x == ch[fa[x]][1];
}
void pushdown(int cur) {
    if(cur && ver[cur]) {
        ver[ch[cur][0]] ^= 1;
        ver[ch[cur][1]] ^= 1;
        swap(ch[cur][0], ch[cur][1]);
        ver[cur] = 0;
    }
}
void rotate(int x) {
    int y = fa[x], z = fa[y], chk = get(x);
    pushdown(x);
    pushdown(y);
    ch[y][chk] = ch[x][chk ^ 1];
    if(ch[x][chk ^ 1]) fa[ch[x][chk ^ 1]] = y;
    ch[x][chk ^ 1] = y;
    fa[y] = x;
    fa[x] = z;
    if(z) ch[z][y == ch[z][1]] = x;
    maintain(x);
    maintain(y);
}
void splay(int x, int to) {
    for(int f = fa[x];f = fa[x], f != to;rotate(x)) {
        if(fa[f] != to) rotate(get(f) == get(x) ? f : x);
    }
    if(to == 0) rt = x;
}
void ins(int k) {
    if(!rt) {
        val[++tot] = k;
        cnt[tot] = 1;
        rt = tot;
        maintain(tot);
        return;
    }
    int cur = rt, f = 0;
    while(1) {
        if(val[cur] == k) {
            cnt[cur] ++;
            maintain(cur);
            maintain(f);
            splay(cur, 0);
            return;
        }
        f = cur;
        cur = ch[cur][val[cur] < k];
        if(!cur) {
            val[++tot] = k;
            cnt[tot] = 1;
            ch[f][val[f] < k] = tot;
            fa[tot] = f;
            maintain(tot);
            maintain(f);
            splay(tot, 0);
            return;
        }
    }
}
int kth(int k) {
    int cur = rt;
    while(1) {
        pushdown(cur);
        if(ch[cur][0] && sz[ch[cur][0]] >= k) cur = ch[cur][0];
        else {
            k -= (sz[ch[cur][0]] + cnt[cur]);
            if(k <= 0) {
                splay(cur, 0);
                return cur;
            }
            cur = ch[cur][1];
        }
    }
}
void work(int x, int y) {
    int l = kth(x - 1);
    int r = kth(y + 1);
    splay(l, 0);
    splay(r, l);
    int cur = ch[rt][1];
    cur = ch[cur][0];
    ver[cur] ^= 1;
}
void print(int x) {
    pushdown(x);
    if(ch[x][0]) print(ch[x][0]);
    if(val[x] != 2147483647 && val[x] != -2147483647) {
        cout << val[x] << " ";
    }
    if(ch[x][1]) print(ch[x][1]);
}
int main() {
    scanf("%d%d", &n, &m);
    ins(2147483647);
    ins(-2147483647);
    for(int i = 1;i <= n;i++) ins(i);
    while(m --) {
        int l, r;
        scanf("%d%d", &l, &r);
        work(l + 1, r + 1);
    }
    print(rt);
}