Submission #1066792

#	Time	Username	Problem	Language	Result	Execution time	Memory
1066792		vjudge1	Building Bridges (CEOI17_building)	C++17	0 / 100	27 ms	5212 KiB

building

#include <bits/stdc++.h>
using namespace std;
#define fi first
#define se second
#define pu push_back
#define ll long long
typedef pair <long,long> ii;
const int N=1e6;
long long mod=1e9;
long n,m,k;
long a[N+1],g[N+10];
ll dp[N+1];
ii b[N+10];

struct Line {
	mutable ll k, m, p;
	bool operator<(const Line& o) const { return k > o.k; }
	bool operator<(ll x) const { return p < x; }
};

struct Linecontain : multiset<Line, less<>> {

	static const ll inf = LLONG_MAX;
	ll div(ll a, ll b) {
		return a / b - ((a ^ b) < 0 && a % b); }
	bool isect(iterator x, iterator y) {
		if (y == end()) return x->p = inf, 0;
		if (x->k == y->k) x->p = x->m > y->m ? inf : 0;
		else x->p = div(y->m - x->m, x->k - y->k);
		return x->p >= y->p;
	}
	void add(ll k, ll m) {
		auto z = insert({k, m, 0}), y = z++, x = y;
		while (isect(y, z)) z = erase(z);
		if (x != begin() && isect(--x, y)) isect(x, y = erase(y));
		while ((y = x) != begin() && (--x)->p >= y->p)
			isect(x, erase(y));
	}
	ll query(ll x) {
		assert(!empty());
		auto l = *lower_bound(x);
		return l.k * x + l.m;
	}
};
Linecontain lc;
Line l[N+1],s[N+1],S[N+1];
double e[N+1];


void tinh(){
    cin>>n;
    for(long i=1;i<=n;i++) {cin>>b[i].fi;}
    for(int i=1;i<=n;i++) cin>>b[i].se;
    g[n+1]=0;
    for(int i=n;i>=1;i--) {g[i]=g[i+1]+b[i].se;
    }
    k=1;
    /*
    6
    3 8 7 1 6 6
    0 -1 9 1 2 0
    */
    l[1].m=b[1].fi*b[1].fi+g[2];

    l[1].k=-2*b[1].fi;
    lc.add(l[1].k,l[1].m);
    dp[1]=0;
    for(long i=2;i<=n;i++){
        long A=-2*b[i].fi,B=0;
        ll res=lc.query(b[i].fi)+b[i].fi*b[i].fi - g[i];
        dp[i]=res;
        B=dp[i]+g[i+1]+b[i].fi*b[i].fi;
        lc.add(A,B);
        //cout<<res<<"\n";

     }
    cout<<dp[n];
    }
int main(){
    //freopen("jday.inp","r",stdin);
    //freopen("jday.out","w",stdout);
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    cout.tie(0);
    tinh();
    return 0;

}
//code của anh Nam đẹp trai nhất CHL

• Subtask 1: 0 / 30
• Subtask 2: 0 / 30
• Subtask 3: 0 / 40