Submission #881821

#	Time	Username	Problem	Language	Result	Execution time	Memory
881821		abysmal	Building Bridges (CEOI17_building)	C++14	100 / 100	40 ms	10580 KiB

building

#include<iostream>
#include<stdio.h>
#include<stdint.h>
#include<iomanip>
#include<algorithm>
#include<utility>
#include<vector>
#include<stack>
#include<queue>
#include<set>
#include<map>
#include<deque>
#include<math.h>
#include<assert.h>
#include<string.h>
#include<chrono>
#include<bitset>

using namespace std;
using namespace std::chrono;

const int64_t INF = (int64_t) 9e18 + 100;
const int64_t mINF = (int64_t) 1e6 + 5;
const int64_t MOD = 1e9;
const int64_t MOD2 = 998244353;
const int nbit = 63;
const int ndig = 10;
const int nchar = 26;
const int p1 = 31;
const int p2 = 53;
const int D = 4;
int dr[D] = {-1, 0, 1, 0};
int dc[D] = {0, 1, 0, -1};
const int Dk = 8;
int drk[Dk] = {2, 2, -2, -2, 1, 1, -1, -1};
int dck[Dk] = {1, -1, 1, -1, 2, -2, 2, -2};
bool Q = false;

struct Line
{
    int64_t k;
    int64_t m;
    mutable int64_t p;

    bool operator < (const Line& o) const
    {
        if(Q) return p < o.p;
        return k < o.k;
    }
};

struct LineContainer : multiset<Line, less<> >
{
    int64_t div(int64_t a, int64_t b)
    {
        return a / b - ((a ^ b) < 0 && a % b);
    }

    bool isect(iterator x, iterator y)
    {
        if(y == end())
        {
            x->p = INF;
            return false;
        }

        if(x->k == y->k)
        {
            if(x->m > y->m) x->p = INF;
            else x->p = -INF;
        }
        else x->p = div(y->m - x->m, x->k - y->k);

        return x->p >= y->p;
    }

    void add(int64_t k, int64_t m)
    {
        auto z = insert({-k, -m, 0});
        auto y = z++;
        auto 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));
    }

    int64_t query(int64_t x)
    {
        assert(!empty());

        Q = true;
        auto l = *lower_bound({0, 0, x});
        Q = false;

        return -(l.k * x + l.m);
    }
};

struct Solution
{
    int n;
    vector<int64_t> h;
    vector<int64_t> w;
    vector<int64_t> suffix;

    Solution() {}

    void solve()
    {
        cin >> n;
        h.resize(n, 0);
        w.resize(n, 0);
        suffix.resize(n + 1, 0);
        for(int i = 0; i < n; i++)
        {
            cin >> h[i];
        }

        for(int i = 0; i < n; i++)
        {
            cin >> w[i];
        }

        for(int i = n - 1; i >= 0; i--)
        {
            suffix[i] = suffix[i + 1] + w[i];
        }

        LineContainer lc;
        vector<int64_t> dp(n, -INF);
        dp[0] = 0;
        for(int i = 0; i < n; i++)
        {
            if(i != 0)
            {
                int64_t max_ = lc.query(h[i]);
                dp[i] = h[i] * h[i] + max_ - suffix[i];
            }

            lc.add(-2 * h[i], h[i] * h[i] + suffix[i + 1] + dp[i]);
        }

        cout << dp[n - 1] << "\n";
    }

    int modadd(int t1, int t2)
    {
        int res = t1 + t2;
        if(res >= MOD) res -= MOD;
        return res;
    }

    int modsub(int t1, int t2)
    {
        int res = t1 - t2;
        if(res < 0) res += MOD;
        return res;
    }

    int modmul(int t1, int t2)
    {
        int64_t res = 1LL * t1 * t2;
        return res % MOD;
    }

    int Abs(int t1)
    {
        if(t1 < 0) return -t1;
        return t1;
    }

    int64_t MASK(int j)
    {
        return (1LL << j);
    }

    bool BIT(int64_t t1, int j)
    {
        return (t1 & MASK(j));
    }
};

void __setup()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL); cout.tie(NULL);

//    freopen("XAYCAU.INP", "r", stdin);
//    freopen("XAYCAU.OUT", "w", stdout);
}

int main()
{
    __setup();
//        auto start = high_resolution_clock::now();
    int t = 1;
//    cin >> t;
    for(int i = 1; i <= t; i++)
    {
        Solution().solve();
    }

//    auto stop = high_resolution_clock::now();
//    auto duration = duration_cast<microseconds>(stop - start);
//    cerr << duration.count() << "\n";
    return 0;
}

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