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답안 #62710

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
62710 2018-07-29T21:25:53 Z eriksuenderhauf Building Bridges (CEOI17_building) C++11
100 / 100
 89 ms 9960 KB 
#include <bits/stdc++.h>
#include <unordered_map>
#include <unordered_set>
#include <stack>
#include <queue>
#include <deque>
#include <string>
#include <fstream>
#define ni(n) scanf("%d", &n)
#define nl(n) scanf("%lld", &n)
#define nai(a,n) for (int i = 0; i < (n); i++) ni((a)[i])
#define nal(a,n) for (int i = 0; i < (n); i++) nl((a)[i])
#define case(t) printf("Case #%d: ", (t))
#define pii pair<int, int>
#define vii vector<pii>
#define vi vector<int>
#define pb push_back
#define mp make_pair
#define f first
#define s second
typedef long long ll;
const double pi = acos(-1);
const int MOD = 1e9 + 7;
const ll INF = 1e18 + 7;
const int MAXN = 1e5 + 5;
const double eps = 1e-9;
using namespace std;
ll h[MAXN], w[MAXN], pre[MAXN], dp[MAXN];
bool q = false;

struct Line
{
    ll m, n;
    mutable double p;

    const bool operator<(Line rhs) const
    {
        return q ? p < rhs.p : m < rhs.m;
    }
};

struct Hull
{
    multiset<Line> lines;

    bool bad(multiset<Line>::iterator x, multiset<Line>::iterator y)
    {
        if (y == lines.end())
        {
            x->p = INF;
            return false;
        }
        if (x->m == y->m)
            x->p = x->n > y->n ? INF : -INF;
        else
            x->p = ((double) y->n - x->n) / ((double) x->m - y->m);
        return x->p >= y->p;
    }

    void add(ll m, ll n)
    {
        multiset<Line>::iterator z = lines.insert({m, n, 0});
        multiset<Line>::iterator y = z++;
        multiset<Line>::iterator x = y;
        while (bad(y, z))
            z = lines.erase(z);
        if (x != lines.begin() && bad(--x, y))
            bad(x, y = lines.erase(y));
        while ((y = x) != lines.begin() && (--x)->p >= y->p)
            bad(x, lines.erase(y));
    }

    ll query(ll x)
    {
        q = true;
        Line l = *lines.lower_bound({0, 0, x});
        q = false;
        return l.m * x + l.n;
    }
};

int main()
{
    int n;
    ni(n);
    nal(h, n);
    nal(w, n);
    for (int i = 1; i < n; i++)
        pre[i] = pre[i - 1] + w[i];
    Hull hu;
    hu.add(2 * h[0], -h[0] * h[0]);
    for (int i = 1; i < n; i++)
    {
        dp[i] = -hu.query(h[i]) + pre[i - 1] + h[i] * h[i];
        hu.add(2 * h[i], -dp[i] + pre[i] - h[i] * h[i]);
    }
    printf("%lld\n", dp[n - 1]);
    return 0;
}

Compilation message

building.cpp: In member function 'll Hull::query(ll)':
building.cpp:76:46: warning: narrowing conversion of 'x' from 'll {aka long long int}' to 'double' inside { } [-Wnarrowing]
         Line l = *lines.lower_bound({0, 0, x});
                                              ^
building.cpp: In function 'int main()':
building.cpp:9:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 #define ni(n) scanf("%d", &n)
               ~~~~~^~~~~~~~~~
building.cpp:85:5: note: in expansion of macro 'ni'
     ni(n);
     ^~
building.cpp:10:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 #define nl(n) scanf("%lld", &n)
               ~~~~~^~~~~~~~~~~~
building.cpp:12:48: note: in expansion of macro 'nl'
 #define nal(a,n) for (int i = 0; i < (n); i++) nl((a)[i])
                                                ^~
building.cpp:86:5: note: in expansion of macro 'nal'
     nal(h, n);
     ^~~
building.cpp:10:20: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
 #define nl(n) scanf("%lld", &n)
               ~~~~~^~~~~~~~~~~~
building.cpp:12:48: note: in expansion of macro 'nl'
 #define nal(a,n) for (int i = 0; i < (n); i++) nl((a)[i])
                                                ^~
building.cpp:87:5: note: in expansion of macro 'nal'
     nal(w, n);
     ^~~

Subtask #1
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 3 ms 412 KB Output is correct
4 Correct 3 ms 540 KB Output is correct
5 Correct 3 ms 540 KB Output is correct

Subtask #2
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 76 ms 3676 KB Output is correct
2 Correct 65 ms 3724 KB Output is correct
3 Correct 66 ms 3732 KB Output is correct
4 Correct 62 ms 3732 KB Output is correct
5 Correct 55 ms 4900 KB Output is correct

Subtask #3
40.0 / 40.0

# 결과 실행 시간 메모리 Grader output
1 Correct 2 ms 376 KB Output is correct
2 Correct 2 ms 376 KB Output is correct
3 Correct 3 ms 412 KB Output is correct
4 Correct 3 ms 540 KB Output is correct
5 Correct 3 ms 540 KB Output is correct
6 Correct 76 ms 3676 KB Output is correct
7 Correct 65 ms 3724 KB Output is correct
8 Correct 66 ms 3732 KB Output is correct
9 Correct 62 ms 3732 KB Output is correct
10 Correct 55 ms 4900 KB Output is correct
11 Correct 64 ms 4900 KB Output is correct
12 Correct 89 ms 4900 KB Output is correct
13 Correct 51 ms 4900 KB Output is correct
14 Correct 88 ms 4900 KB Output is correct
15 Correct 77 ms 9960 KB Output is correct
16 Correct 57 ms 9960 KB Output is correct
17 Correct 34 ms 9960 KB Output is correct
18 Correct 39 ms 9960 KB Output is correct