Solution - P4254 [JSOI2008] Blue Mary 开公司

比模板还模板的李超线段树题。

有一个坑：收益必须是非负的，负的也得是非负的。

特别纸张。

#include <bits/stdc++.h>
#define llong long long
#define N 100005
using namespace std;

constexpr double eps = 1e-6;
inline int cmp(double a, double b){
    if(fabs(a-b) < eps) return 0;
    return a>b ? 1 : -1;
}

int n;

struct Seg{
    double k, b;
    bool vis;
};
inline double asky(Seg s, int x){return s.k*x+s.b;}

constexpr int T = 50000;
Seg val[(T<<2)+5];
#define ls(x) (x<<1)
#define rs(x) (x<<1|1)
#define mid ((l+r)>>1)

inline void insert(Seg k, int x = 1, int l = 1, int r = T){
    if(!val[x].vis){
        val[x] = k;
        return;
    }
    Seg s1 = val[x], s2 = k;
    if(cmp(asky(s1, mid), asky(s2, mid)) < 0) swap(s1, s2);
    val[x] = s1;
    if(cmp(asky(s1, l), asky(s2, l)) < 0) insert(s2, ls(x), l, mid  );
    if(cmp(asky(s1, r), asky(s2, r)) < 0) insert(s2, rs(x), mid+1, r);
    return;
}
inline double query(int pos, int x = 1, int l = 1, int r = T){
    double res = -1e18;
    if(val[x].vis) res = asky(val[x], pos);
    if(l == r) return res;
    if(pos <= mid) res = max(res, query(pos, ls(x), l, mid  ));
    else           res = max(res, query(pos, rs(x), mid+1, r));
    return res;
}

int main(){
    scanf("%d", &n);
    insert((Seg){0, 0, true});
    for(int i = 1; i <= n; ++i){
        char op[15];
        scanf("%s", op);
        if(op[0] == 'P'){
            Seg s;
            scanf("%lf %lf", &s.b, &s.k), s.b -= s.k, s.vis = true;
            insert(s);
        }
        if(op[0] == 'Q'){
            int t; double res;
            scanf("%d", &t);
            res = query(t);
            if(res <= -1e18) puts("0");
            else printf("%d\n", (int)((res+eps)/100));
        }
    }
    return 0;
}