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답안 #240200

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
240200 2020-06-18T14:25:42 Z rqi Building Bridges (CEOI17_building) C++14
100 / 100
 63 ms 9848 KB 
#include <bits/stdc++.h>
using namespace std;
 
typedef long long ll;
typedef long double ld;
typedef double db; 
typedef string str; 

typedef pair<int,int> pi;
typedef pair<ll,ll> pl; 
typedef pair<db,db> pd; 

typedef vector<int> vi; 
typedef vector<ll> vl; 
typedef vector<db> vd; 
typedef vector<str> vs; 
typedef vector<pi> vpi;
typedef vector<pl> vpl; 
typedef vector<pd> vpd; 

#define mp make_pair
#define f first
#define s second
#define sz(x) (int)x.size()
#define all(x) begin(x), end(x)
#define rall(x) (x).rbegin(), (x).rend() 
#define rsz resize
#define ins insert 
#define ft front() 
#define bk back()
#define pf push_front 
#define pb push_back
#define eb emplace_back 
#define lb lower_bound 
#define ub upper_bound 

#define FOR(i,a,b) for (int i = (a); i < (b); ++i)
#define F0R(i,a) FOR(i,0,a)
#define ROF(i,a,b) for (int i = (b)-1; i >= (a); --i)
#define R0F(i,a) ROF(i,0,a)
#define trav(a,x) for (auto& a: x)

const int MOD = 1e9+7; // 998244353;
const int MX = 2e5+5; 
const ll INF = 1e18; 
const ld PI = acos((ld)-1);
const int xd[4] = {1,0,-1,0}, yd[4] = {0,1,0,-1}; 
mt19937 rng((uint32_t)chrono::steady_clock::now().time_since_epoch().count()); 

template<class T> bool ckmin(T& a, const T& b) { 
    return b < a ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { 
    return a < b ? a = b, 1 : 0; } 
int pct(int x) { return __builtin_popcount(x); } 
int bits(int x) { return 31-__builtin_clz(x); } // floor(log2(x)) 
int cdiv(int a, int b) { return a/b+!(a<0||a%b == 0); } // division of a by b rounded up, assumes b > 0 
int fstTrue(function<bool(int)> f, int lo, int hi) {
    hi ++; assert(lo <= hi); // assuming f is increasing
    while (lo < hi) { // find first index such that f is true 
        int mid = (lo+hi)/2; 
        f(mid) ? hi = mid : lo = mid+1; 
    } 
    return lo;
}

// INPUT
template<class A> void re(complex<A>& c);
template<class A, class B> void re(pair<A,B>& p);
template<class A> void re(vector<A>& v);
template<class A, size_t SZ> void re(array<A,SZ>& a);

template<class T> void re(T& x) { cin >> x; }
void re(db& d) { str t; re(t); d = stod(t); }
void re(ld& d) { str t; re(t); d = stold(t); }
template<class H, class... T> void re(H& h, T&... t) { re(h); re(t...); }

template<class A> void re(complex<A>& c) { A a,b; re(a,b); c = {a,b}; }
template<class A, class B> void re(pair<A,B>& p) { re(p.f,p.s); }
template<class A> void re(vector<A>& x) { trav(a,x) re(a); }
template<class A, size_t SZ> void re(array<A,SZ>& x) { trav(a,x) re(a); }

// TO_STRING
#define ts to_string
str ts(char c) { return str(1,c); }
str ts(bool b) { return b ? "true" : "false"; }
str ts(const char* s) { return (str)s; }
str ts(str s) { return s; }
template<class A> str ts(complex<A> c) { 
    stringstream ss; ss << c; return ss.str(); }
str ts(vector<bool> v) { 
    str res = "{"; F0R(i,sz(v)) res += char('0'+v[i]);
    res += "}"; return res; }
template<size_t SZ> str ts(bitset<SZ> b) {
    str res = ""; F0R(i,SZ) res += char('0'+b[i]);
    return res; }
template<class A, class B> str ts(pair<A,B> p);
template<class T> str ts(T v) { // containers with begin(), end()
    bool fst = 1; str res = "{";
    for (const auto& x: v) {
        if (!fst) res += ", ";
        fst = 0; res += ts(x);
    }
    res += "}"; return res;
}
template<class A, class B> str ts(pair<A,B> p) {
    return "("+ts(p.f)+", "+ts(p.s)+")"; }

// OUTPUT
template<class A> void pr(A x) { cout << ts(x); }
template<class H, class... T> void pr(const H& h, const T&... t) { 
    pr(h); pr(t...); }
void ps() { pr("\n"); } // print w/ spaces
template<class H, class... T> void ps(const H& h, const T&... t) { 
    pr(h); if (sizeof...(t)) pr(" "); ps(t...); }

// DEBUG
void DBG() { cerr << "]" << endl; }
template<class H, class... T> void DBG(H h, T... t) {
    cerr << ts(h); if (sizeof...(t)) cerr << ", ";
    DBG(t...); }
#ifdef LOCAL // compile with -DLOCAL
#define dbg(...) cerr << "LINE(" << __LINE__ << ") -> [" << #__VA_ARGS__ << "]: [", DBG(__VA_ARGS__)
#else
#define dbg(...) 0
#endif

// FILE I/O
void setIn(string s) { freopen(s.c_str(),"r",stdin); }
void setOut(string s) { freopen(s.c_str(),"w",stdout); }
void unsyncIO() { ios_base::sync_with_stdio(0); cin.tie(0); }
void setIO(string s = "") {
    unsyncIO();
    // cin.exceptions(cin.failbit); 
    // throws exception when do smth illegal
    // ex. try to read letter into int
    if (sz(s)) { setIn(s+".in"), setOut(s+".out"); } // for USACO
}

/**
 * Description: LineContainer; add lines of the form $kx+m$, 
     * compute greatest $y$-coordinate for any $x$.
 * Time: O(\log N)
 * Source: KACTL
   * https://github.com/kth-competitive-programming/kactl/commit/165807e28402c9be906f6e6a09452431787bb70d?diff=unified
 * Verification: 
   * CSA Squared Ends not working :(
   * https://codeforces.com/contest/1083/problem/E
   * https://atcoder.jp/contests/arc066/tasks/arc066_d
 */

bool Q;
struct Line {
    mutable ll k, m, p; // slope, y-intercept, last optimal x
    ll eval (ll x) { return k*x+m; }
    bool operator<(const Line& o) const { return Q?p<o.p:k<o.k; }
};

// for doubles, use inf = 1/.0, divi(a,b) = a/b
const ll inf = LLONG_MAX;
// floored div
ll divi(ll a, ll b) { return a/b-((a^b) < 0 && a%b); } 
// last x such that first line is better
ll bet(const Line& x, const Line& y) { 
    if (x.k == y.k) return x.m >= y.m ? inf : -inf;
    return divi(y.m-x.m,x.k-y.k); }

struct LC : multiset<Line> { 
    // updates x->p, determines if y is unneeded
    bool isect(iterator x, iterator y) { 
        if (y == end()) { x->p = inf; return 0; }
        x->p = bet(*x,*y); return x->p >= y->p; }
    void add(ll k, ll m) {
        k = -k;
        m = -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());
        Q = 1; auto l = *lb({0,0,x}); Q = 0;
        return -(l.k*x+l.m);
    }
};



const int mx = 100005;
ll h[mx];
ll w[mx];
LC lin;
ll dp[mx];

int main() {
    setIO();
    int n;
    cin >> n;
    for(int i = 1; i <= n; i++){
        cin >> h[i];
    }
    ll ians = 0;
    for(int i = 1; i <= n; i++){
        cin >> w[i];
        ians+=w[i];
        w[i] = -w[i];
    }

    dp[1] = w[1];
    lin.add(-2*h[1], dp[1]+h[1]*h[1]);

    for(int i = 2; i <= n; i++){
        dp[i] = lin.query(h[i]);
        dp[i]+=h[i]*h[i]+w[i];
        lin.add(-2*h[i], dp[i]+h[i]*h[i]);
    }

    ll fans = ians+dp[n];
    ps(fans);

    // you should actually read the stuff at the bottom
}

/* stuff you should look for
    * int overflow, array bounds
    * special cases (n=1?)
    * do smth instead of nothing and stay organized
    * WRITE STUFF DOWN
*/

Compilation message

building.cpp: In function 'void setIn(std::__cxx11::string)':
building.cpp:128:31: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
 void setIn(string s) { freopen(s.c_str(),"r",stdin); }
                        ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
building.cpp: In function 'void setOut(std::__cxx11::string)':
building.cpp:129:32: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
 void setOut(string s) { freopen(s.c_str(),"w",stdout); }
                         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

Subtask #1
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 256 KB Output is correct
2 Correct 5 ms 384 KB Output is correct
3 Correct 5 ms 384 KB Output is correct
4 Correct 5 ms 416 KB Output is correct
5 Correct 6 ms 384 KB Output is correct

Subtask #2
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 55 ms 3832 KB Output is correct
2 Correct 54 ms 3832 KB Output is correct
3 Correct 54 ms 3832 KB Output is correct
4 Correct 48 ms 3664 KB Output is correct
5 Correct 46 ms 4856 KB Output is correct

Subtask #3
40.0 / 40.0

# 결과 실행 시간 메모리 Grader output
1 Correct 4 ms 256 KB Output is correct
2 Correct 5 ms 384 KB Output is correct
3 Correct 5 ms 384 KB Output is correct
4 Correct 5 ms 416 KB Output is correct
5 Correct 6 ms 384 KB Output is correct
6 Correct 55 ms 3832 KB Output is correct
7 Correct 54 ms 3832 KB Output is correct
8 Correct 54 ms 3832 KB Output is correct
9 Correct 48 ms 3664 KB Output is correct
10 Correct 46 ms 4856 KB Output is correct
11 Correct 54 ms 3960 KB Output is correct
12 Correct 54 ms 3704 KB Output is correct
13 Correct 43 ms 3832 KB Output is correct
14 Correct 53 ms 3960 KB Output is correct
15 Correct 63 ms 9848 KB Output is correct
16 Correct 44 ms 4984 KB Output is correct
17 Correct 30 ms 3704 KB Output is correct
18 Correct 32 ms 3704 KB Output is correct