萌新求助LCT，代码轻工业

#include <bits/stdc++.h>
using namespace std;
const int N = 39989, M = 1e9;
using T = long double;
const T eps = 1e-7;
int i, j, n, m, op, a, b, x, y, ls, rt, id;
struct func {
    T k, b; int id;
    func(T k=0, T b=-1e17, int id=0) : k(k), b(b), id(id){}
    T operator () (int x) {return (T)(1.0 * k * x + b);}
};
struct yuki {
    func tag[N + 7 << 1];
    int L[N + 7 << 1], R[N + 7 << 1], tot;
    func mv(func a, func b, int x) {return a(x) < b(x) ? b : a;}
    func md(func a, func b, int x) {return a.id > b.id ? b : a;}
    func mx(func a, func b, int x) {return a(x) == b(x) ? md(a, b, x) : mv(a, b, x);}
    void ins(func f, int& p, int l, int r) {
        if(!p) p = ++tot; int mid = l + r >> 1;
        switch((f(l) <= tag[p](l)) + (f(r) <= tag[p](r))) {
            case 0: tag[p] = f; break;
            case 1: ins(f, L[p], l, mid), ins(f, R[p], mid + 1, r); break;
        }
    }
    func query(int x, int p=rt, int l=1, int r=N) {
        if(!p) return func(); int mid = l + r >> 1;
        return mx(tag[p], x <= mid ? query(x, L[p], l, mid) : query(x, R[p], mid + 1, r), x);
    }
    void modify(int x, int y, func f, int& p=rt, int l=1, int r=N) {
        if(!p) p = ++tot; int mid = l + r >> 1;
        if(x <= l && r <= y) return ins(f, p, l, r);
        if(x <= mid) modify(x, y, f, L[p], l, mid);
        if(y > mid) modify(x, y, f, R[p], mid + 1, r);
    }
} miku;
int main() {
    ios::sync_with_stdio(false);
    cin.tie(0), cout.tie(0);
    cin >> n;
    for(i=1; i<=n; i++) {
        cin >> op;
        if(op) {
            cin >> a >> b >> x >> y;
            a = (a + ls - 1) % N + 1;
            b = (b + ls - 1) % N + 1;
            x = (x + ls - 1) % M + 1;
            y = (y + ls - 1) % M + 1;
            func f; f.id = ++id;
            if(x ^ a) {
                f.k = (T)1.0 * (y - b) / (T)(x - a);
                f.b = (T)(y - (T)f.k * x);
            } else {
                f.k = 0, f.b = max(y, b);
            }
            miku.modify(min(a, x), max(a, x), f);
        } else {
            cin >> x, x = (x + ls - 1) % N + 1;
            cout << (ls = miku.query(x).id) << "\n";
        }
    }
    return 0;
}