Submission #257442

#	Time	Username	Problem	Language	Result	Execution time	Memory
257442		kym	Discharging (NOI20_discharging)	C++17	100 / 100	167 ms	17912 KiB

Discharging

#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
#pragma GCC target("avx,avx2,fma")
using namespace std;
#define int ll 
#define FOR(i,s,e) for(ll i = s; i <= (ll)e; ++i)
#define DEC(i,s,e) for(ll i = s; i >= (ll)e; --i)
#define IAMSPEED ios_base::sync_with_stdio(false); cin.tie(0);
#define db(x) cerr << #x << "=" << x << "\n"
#define db2(x, y) cerr << #x << "=" << x << " , " << #y << "=" << y << "\n"
#define db3(a,b,c) cerr<<#a<<"="<<a<<","<<#b<<"="<<b<<","<<#c<<"="<<c<<"\n"
#define dbv(v) cerr << #v << ":"; for (auto ite : v) cerr << ite << ' '; cerr <<"\n"
#define dbvp(v) cerr << #v << ":"; for (auto ite : v) cerr << "{"  << ite.f << ',' << ite.s << "} "; cerr << "\n"
#define dba(a,ss,ee) cerr << #a << ":"; FOR(ite,ss,ee) cerr << a[ite] << ' '; cerr << "\n"
mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());
#define ll long long 
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define f first
#define s second
#define reach cerr << "LINE: " << __LINE__ << "\n";
typedef pair <ll, ll> pi;
typedef tuple<ll,ll,ll> ti3;
string cts(char x) {string t(1,x); return t;}
ll rand(ll a, ll b) { return a + rng() % (b-a+1); }
const int MOD = 1e9 + 7;
const int inf = (int)1e9 + 500;
const long long oo = (ll)1e18 + 500;
template <typename T> void chmax(T& a, T b) { a = max(a, b); }
template <typename T> void chmin(T& a, T b) { a = min(a, b); }
const int MAXN = 1000005;
#ifndef LOCAL
#define cerr if(0)cout
#endif

struct ConvexHull {
    deque<pi> dq;
    int f(pi line, int x) {
        return line.first*x + line.second;
    }
    int query(int x) {
        while(dq.size()>1) {
            if(f(dq[0],x)>f(dq[1],x)) {
                dq.pop_front();
            } else {
                break;
            }
        }
        return f(dq[0],x);
    }
    double intersect(int m1, int c1, int m2, int c2) {
        return (double) (c2-c1)/(m1-m2);
    }
    double intersect(pi a, pi b) {
        return intersect(a.first,a.second,b.first,b.second);
    }
    void insert(pi line) {
        while(dq.size() > 1) {
            int s = dq.size();
            if(intersect(dq[s-1],line) <= intersect(dq[s-2],line)) {
                dq.pop_back();
            } else {
                break;
            }
        }
        dq.push_back(line);
    }
} CH;
//dp(i) = dp(j) + A[i] * (N-i)
//dp(i) = dp(j) + nA[i] - iA[i]

int A[MAXN];
int32_t main() 
{
	IAMSPEED
	int n; cin >> n;
	FOR(i,1,n)cin>>A[i];
	int mx=-1;
	CH.insert({0,0});
	int dp=0;
	FOR(i,1,n) {
		if(A[i]>=mx) {
			mx=A[i];
			dp=CH.query(A[i])+n*A[i];
			CH.insert({-i,dp});
		} else {
			CH.insert({-i,dp});
		}
		dbvp(CH.dq);
	}
	cout << dp;
}

• Subtask 1: 9 / 9
• Subtask 2: 13 / 13
• Subtask 3: 25 / 25
• Subtask 4: 11 / 11
• Subtask 5: 14 / 14
• Subtask 6: 28 / 28