fhqtreap 0pts 求助，样例可过qwq 悬关

#include <bits/stdc++.h>
#define int long long
using namespace std;

int n, m, idx, rt;
struct TREAP {
    int pos, size, val, lson, rson, flag;
} t[100010];

void pushup(int u) {
    t[u].size = t[t[u].lson].size+t[t[u].rson].size+1;
}
int build(int x) {
    t[++idx].val = x, t[idx].size = 1, t[idx].pos = rand();
    return idx;
}
void pushdown(int u) {
    swap(t[u].lson, t[u].rson);
    if(t[u].lson) t[t[u].lson].flag ^= 1;
    if(t[u].rson) t[t[u].rson].flag ^= 1;
    t[u].flag = 0;
}
int merge(int u, int v) {
    if(!u || !v) return u+v;
    if(t[u].pos < t[v].pos) {
        if(t[u].flag) pushdown(u);
        t[u].rson = merge(t[u].rson, v);
        pushup(u);
        return u;
    }
    if(t[v].flag) pushdown(v);
    t[v].lson = merge(t[v].lson, u);
    pushup(v);
    return v;
}
void split(int x, int y, int &u, int &v) {
    if(!x) {
        u = v = 0;
        return;
    }
    if(t[x].flag) pushdown(x);
    if(t[t[x].lson].size < y)
        u = x, split(t[x].rson, y-t[t[x].lson].size-1, t[x].rson, v);
    else v = x, split(t[x].lson, y, u, t[x].lson);
    pushup(x);
}
void dfs(int u) {
    if(!u) return;
    if(t[u].flag) pushdown(u);
    dfs(t[u].lson);
    printf("%lld ", t[u].val);
    dfs(t[u].rson);
}

signed main() {
    scanf("%lld%lld", &n, &m);
    for(int i = 1; i <= n; i++) 
        rt = merge(rt, build(i));
    for(int i = 1; i <= m; i++) {
        int l, r, a = 0, b = 0, c = 0;
        scanf("%lld%lld", &l, &r);
        split(rt, l-1, a, b), split(b, r-l+1, b, c);
        t[b].flag ^= 1, rt = merge(a, merge(b, c));
    }
    dfs(rt);

    return 0;
}