Submission #908101

# Submission time Handle Problem Language Result Execution time Memory
908101 2024-01-16T07:56:03 Z wii Building Bridges (CEOI17_building) C++17
100 / 100
42 ms 15952 KB
#include <bits/stdc++.h>
using namespace std;

typedef double db;
typedef long long ll;
typedef long double ld;

#define int ll
typedef pair<int, int> pii;

#define lx (id << 1)
#define rx (lx | 1)
#define gcd __gcd
#define pb push_back
#define all(x) (x).begin(), (x).end()
#define bit(i, mask) ((mask) >> (i) & 1)
#define reset(x, val) memset(x, val, sizeof(x))
#define foru(i,a,b) for(int i = (a); i <= (b); ++i)
#define ford(i,a,b) for(int i = (a); i >= (b); --i)
#define FastIO ios::sync_with_stdio(0), cin.tie(0), cout.tie(0);

template<typename T> bool maximize(T &res, const T &val) { if (res < val) { res = val; return true; } return false; }
template<typename T> bool minimize(T &res, const T &val) { if (val < res) { res = val; return true; } return false; }

const ll Linf = 0x3f3f3f3f3f3f3f3f;
const int Inf = 0x3f3f3f3f;
const ll Mod = 1e9 + 7;
const ll Mod2 = ll(1e9) + 9;
const int Lim = 1e6 + 5;
const int inv6 = 166666668;

// #define Sieve
#ifdef Sieve
    vector<int> pr;
    vector<int> lpf;
    void Linear_sieve(int n = Lim) {
        pr.assign(1, 2);
        lpf.assign(n + 1, 2);

        for (int x = 3; x <= n; x += 2) {
            if (lpf[x] == 2) pr.push_back(lpf[x] = x);
            for (int i = 1; i < pr.size() && pr[i] <= lpf[x] && pr[i] * x <= n; ++i)
                lpf[pr[i] * x] = pr[i];
        }
    }
#endif

// #define Ckn_calc
#ifdef Ckn_calc
    const int LIM = 1e6 + 16;

    int fact[LIM + 10]; /// factorial:         fact[n] = n!
    int invs[LIM + 10]; /// inverse modular:   invs[n] = n^(-1)
    int tcaf[LIM + 10]; /// inverse factorial: tcaf[n] = (n!)^(-1)
    void precal_nck(int n = LIM)
    {
        fact[0] = fact[1] = 1;
        invs[0] = invs[1] = 1;
        tcaf[0] = tcaf[1] = 1;
        for (int i = 2; i <= n; ++i)
        {
            fact[i] = (1LL * fact[i - 1] * i) % Mod;
            invs[i] = Mod - 1LL * (Mod / i) * invs[Mod % i] % Mod;
            tcaf[i] = (1LL * tcaf[i - 1] * invs[i]) % Mod;
        }
    }

    ll C(int n, int k) {
        if (n < k || k < 0) return 0;

        ll res = fact[n];
        res *= tcaf[k], res %= Mod;
        res *= tcaf[n - k], res %= Mod;
        return res;
    }

    ll P(int n, int k) {
        ll res = fact[n];
        res *= tcaf[n - k], res %= Mod;
        return res;
    }
#endif

/// ====*====*====*====*====*====*====*====*====*====*====*====*====*====*====*====*====

const int base = 3;
const int N = 1e6 + 5;
const int K = log2(N) + 1;
const int dx[] = {+1, -1, 0, 0};
const int dy[] = {0, 0, +1, -1};
const int block_size = sqrt(2e9) + 2;

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 LineContainer : multiset<Line, less<>> {
	// (for doubles, use inf = 1/.0, div(a,b) = a/b)
	static const ll inf = LLONG_MAX;
	ll div(ll a, ll b) { // floored division
		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 : -inf;
		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;
	}
};

int n;
int a[N];
int w[N];
int dp[N];

void solve() {
	cin >> n;
	foru(i, 1, n) cin >> a[i];
	foru(i, 1, n) cin >> w[i];

	foru(i, 1, n) w[i] += w[i - 1];

	LineContainer cht;
	foru(i, 2, n) {
		int j = i - 1;
		cht.add(2LL * a[j], -(a[j] * a[j] + dp[j] - w[j]));
		dp[i] = -cht.query(a[i]) + a[i] * a[i] + w[i - 1];
	}

	cout << dp[n];
}

signed main() {
    FastIO;

    #define task "test"
    if (fopen(task".inp", "r")) {
		freopen(task".inp", "r", stdin);
		freopen(task".out", "w", stdout);
	}

    #ifdef Sieve
        Linear_sieve();
    #endif

    #ifdef Ckn_calc
        precal_nck();
    #endif

    int ntest = 1;
    // cin >> ntest;
    while (ntest--) {
        //cout << "Case " << q << ": " << "\n"; 
        solve();
        cout << "\n";
    }

    return 0;
}

/**  /\_/\
 *  (= ._.)
 *  / >TL \>AC
**/

Compilation message

building.cpp: In function 'int main()':
building.cpp:155:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  155 |   freopen(task".inp", "r", stdin);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
building.cpp:156:10: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  156 |   freopen(task".out", "w", stdout);
      |   ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
# Verdict Execution time Memory Grader output
1 Correct 1 ms 4444 KB Output is correct
2 Correct 1 ms 4444 KB Output is correct
3 Correct 1 ms 4444 KB Output is correct
4 Correct 1 ms 4444 KB Output is correct
5 Correct 2 ms 4444 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 33 ms 9808 KB Output is correct
2 Correct 31 ms 9816 KB Output is correct
3 Correct 34 ms 9812 KB Output is correct
4 Correct 29 ms 9552 KB Output is correct
5 Correct 27 ms 10832 KB Output is correct
# Verdict Execution time Memory Grader output
1 Correct 1 ms 4444 KB Output is correct
2 Correct 1 ms 4444 KB Output is correct
3 Correct 1 ms 4444 KB Output is correct
4 Correct 1 ms 4444 KB Output is correct
5 Correct 2 ms 4444 KB Output is correct
6 Correct 33 ms 9808 KB Output is correct
7 Correct 31 ms 9816 KB Output is correct
8 Correct 34 ms 9812 KB Output is correct
9 Correct 29 ms 9552 KB Output is correct
10 Correct 27 ms 10832 KB Output is correct
11 Correct 33 ms 9844 KB Output is correct
12 Correct 33 ms 9784 KB Output is correct
13 Correct 25 ms 9816 KB Output is correct
14 Correct 31 ms 10076 KB Output is correct
15 Correct 42 ms 15952 KB Output is correct
16 Correct 31 ms 10784 KB Output is correct
17 Correct 24 ms 10324 KB Output is correct
18 Correct 17 ms 9972 KB Output is correct