Learning:李超线段树
这玩意儿假啊!
大清早起来突然开始yy,线段树怎么区间加一个等差数列,然后支持区间取max。yy无果,咕咕咕
后来,点开了一道雅礼集训题,哇塞,真的有这种题哎,哇塞,是弱化版哎(只要支持单点取max就好了),但我还是不会做哎,凉凉凉。
进入正文,思想主要是每个区间用一个“暴露”最多的线段进行替代,其余的线段用一个数组记下来(因为是单点最值所以可以直接比较)。然后在加入线段的时候分类讨论一下:
1、新线段完全高于旧线段,那么把旧线段丢到数组里并覆盖。
2、新线段完全低于旧线段,那么直接无视。
3、新旧线段有交点,按交点分治下去。
时间复杂度:(O(n log^2 n))
/*
bzoj3165
*/
#include<algorithm>
#include<iostream>
#include<cstring>
#include<cstdio>
#include<cmath>
using namespace std;
const int MOD1 = 39989;
const int MOD2 = 1000000000;
const int maxn = 100000 + 10;
const int maxt = maxn << 2;
const double eps = 1e-9;
struct anode{
int xa, xb, ya, yb;
double k, b;
anode() {}
anode(int _xa, int _ya, int _xb, int _yb):xa(_xa), ya(_ya), xb(_xb), yb(_yb) {
if(xa == xb) {
k = 0;
b = 1.0 * max(ya,yb);
}
else {
k = (double)(yb - ya) / (xb - xa);
b = (double) ya - k * xa;
}
}
inline double f(int x) {
return (double)k * x + b;
}
}a[maxn];
inline int sgn(double x) { return (x > - eps) - (x < eps); }
inline int cross(int x, int y) { return floor((double)(a[y].b - a[x].b) / (a[x].k - a[y].k)); }
//sgt
int n, t[maxt], pos[maxn], tot;
inline void updata(int x, int id) {
if(!pos[x]) pos[x] = id;
else {
int tmp = sgn(a[pos[x]].f(x) - a[id].f(x));
if(tmp < 0 || (tmp == 0 && pos[x] > id)) pos[x] = id;
}
}
void ins(int u, int l, int r, int p, int q, int id) {
int ls = u << 1, rs = u << 1 | 1;
if(p <= l && r <= q) {
// cout << u << ' ' << l << ' ' << r << endl;
if(!t[u]) {
t[u] = id;
return;
}
int L = sgn(a[t[u]].f(l) - a[id].f(l)) < 0;
int R = sgn(a[t[u]].f(r) - a[id].f(r)) < 0;
if(L && R) t[u] = id;
else if(!L && !R) {
updata(l,id);
updata(r,id);
}
else {
int mid = (l + r) >> 1, tmp = cross(t[u],id);
if(tmp <= mid && L) ins(ls,l,mid,p,q,id);
if(tmp <= mid && R) {
ins(ls,l,mid,p,q,t[u]);
t[u] = id;
}
if(tmp > mid && L) {
ins(rs,mid + 1,r,p,q,t[u]);
t[u] = id;
}
if(tmp > mid && R) ins(rs,mid + 1,r,p,q,id);
}
return;
}
int mid = (l + r) >> 1;
if(p > mid) ins(rs,mid + 1,r,p,q,id);
else if(q < mid + 1) ins(ls,l,mid,p,q,id);
else {
ins(ls,l,mid,p,q,id);
ins(rs,mid + 1,r,p,q,id);
}
}
inline int merge(int x, int y, int k) {
if(!x || !y) return x + y;
int now = sgn(a[x].f(k) - a[y].f(k)), tmp = x;
if(now < 0 || (now == 0 && x > y)) tmp = y;
return tmp;
}
int query(int u, int l, int r, int p) {
int tmp = t[u];
if(l == r) return t[u];
int mid = (l + r) >> 1;
if(p <= mid) {
tmp = merge(tmp,query(u << 1,l,mid,p),p);
return tmp;
}
else {
tmp = merge(tmp,query(u << 1 | 1,mid + 1,r,p),p);
return tmp;
}
}
int main() {
// freopen("data.out","w",stdout);
scanf("%d", &n);
int lastans = 0; tot = 0;
for(int i = 1;i <= n;i ++) {
int op, k, xa, ya, xb, yb; scanf("%d", &op);
// cout << op << ' ';
if(op == 0) {
scanf("%d", &k);
k = (k + lastans - 1) % MOD1 + 1;
// cout << k << endl;
int tmp = query(1,1,MOD1,k);
if(pos[k]) {
int now = sgn(a[tmp].f(k) - a[pos[k]].f(k));
if(now < 0 || (now == 0 && pos[k] > tmp)) tmp = pos[k];
}
lastans = tmp;
printf("%d
", lastans);
}
if(op == 1) {
scanf("%d%d%d%d", &xa, &ya, &xb, &yb);
xa = (xa + lastans - 1) % MOD1 + 1;
xb = (xb + lastans - 1) % MOD1 + 1;
ya = (ya + lastans - 1) % MOD2 + 1;
yb = (yb + lastans - 1) % MOD2 + 1;
// cout << xa << ' ' << xb << ' ' << ya << ' ' << yb << endl;
if(xa > xb) swap(xa,xb), swap(ya,yb);
a[++ tot] = anode(xa,ya,xb,yb);
ins(1,1,MOD1,xa,xb,tot);
}
}
return 0;
}