BZOJ3165: [Heoi2013]Segment(李超線段樹)
阿新 • • 發佈:2019-02-08
bits min str php orz pre inline problem 鏈接
題意
題目鏈接
Sol
李超線段樹板子題。具體原理就不講了。
一開始自己yy著寫差點寫自閉都快把叉積搬出來了。。。
後來看了下litble的寫法才發現原來可以寫的這麽清晰簡潔Orz
#include<bits/stdc++.h> #define pdd pair<double, double> #define MP make_pair #define fi first #define se second using namespace std; const int MAXN = 1e6 + 10, Lim = 1e9; template <typename A, typename B> inline bool chmin(A &a, B b){if(a > b) {a = b; return 1;} return 0;} template <typename A, typename B> inline bool chmax(A &a, B b){if(a < b) {a = b; return 1;} return 0;} inline int read() { char c = getchar(); int x = 0, f = 1; while(c < '0' || c > '9') {if(c == '-') f = -1; c = getchar();} while(c >= '0' && c <= '9') x = x * 10 + c - '0', c = getchar(); return x * f; } int N = 39989, M; int ls[MAXN], rs[MAXN], root, cnt, tot; pdd mx[MAXN]; struct Line { double k, b; int id; }s[MAXN]; pdd get(int x0, int y0, int x1, int y1) { double k = (double) (y1 - y0) / (x1 - x0), b = (double) y0 - k * x0; return {k, b}; } double calc(Line line, int x) { return line.k * x + line.b; } double GetPoint(Line a, Line b) { return (b.b - a.b) / (a.k - b.k); } pdd ret; void Query(int k, int l, int r, int p) {//fi: val se: id if(chmax(ret.fi, calc(s[k], p))) ret.se = s[k].id; if(l == r) return ; int mid = l + r >> 1; if(p <= mid) Query(ls[k], l, mid, p); else Query(rs[k], mid + 1, r, p); } void Modify(int &k, int l, int r, int ql, int qr, Line seg) { if(!k) k = ++tot; int mid = l + r >> 1; if(ql <= l && r <= qr) { if(!s[k].id) {s[k] = seg; return ;} int p = GetPoint(s[k], seg); int pl = calc(s[k], l), pr = calc(s[k], r), nl = calc(seg, l), nr = calc(seg, r); if(pl > nl && pr > nr) return ; if(pl < nl && pr < nr) {s[k] = seg; return ;} if(pl < nl) { if(p > mid) Modify(rs[k], mid + 1, r, mid + 1, r, s[k]), s[k] = seg; else Modify(ls[k], l, mid, l, mid, seg); } else { if(p > mid) Modify(rs[k], mid + 1, r, mid + 1, r, seg); else Modify(ls[k], l, mid, l, mid, s[k]), s[k] = seg; } return ; } if(l == r) return ; if(ql <= mid) Modify(ls[k], l, mid, ql, qr, seg); if(qr > mid) Modify(rs[k], mid + 1, r, ql, qr, seg); } signed main() { M = read(); for(int i = 1, lastans = 0; i <= M; i++) { int opt = read(); if(!opt) { int k = read(), x = (k + lastans - 1) % 39989 + 1; ret.fi = 0; ret.se = 0; Query(root, 1, N, x); printf("%d\n", lastans = (mx[x].fi > ret.fi ? mx[x].se : ret.se)); } else { int x0 = (read() + lastans - 1) % 39989 + 1, y0 = (read() + lastans - 1) % Lim + 1, x1 = (read() + lastans - 1) % 39989 + 1, y1 = (read() + lastans - 1) % Lim + 1; if(x0 > x1) swap(x0, x1), swap(y0, y1); if(x0 == x1 && chmax(mx[x0].fi, max(y0, y1))) mx[x0].se = i; pdd li = get(x0, y0, x1, y1); Modify(root, 1, N, x0, x1, {li.fi, li.se, ++cnt}); } } return 0; }
BZOJ3165: [Heoi2013]Segment(李超線段樹)