제출 #1270256

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
1270256		vuquangsang	Building Bridges (CEOI17_building)	C++20	30 / 100	54 ms	65348 KiB

building

#include <bits/stdc++.h>
using namespace std;

#define     el "\n"
#define     FOR(i,a,b) for(int i = (a), _b = (b); i <= _b; i++)
#define     FORD(i,a,b) for(int i = (a), _b = (b); i >= _b; i--)
#define     pb push_back
#define     fi first
#define     se second
#define     all(x) x.begin(),x.end()
#define     lg(x) __lg(x)
#define     alla(a,n) a+1,a+n+1
#define     ll long long


template <class T> bool maxi(T &x, T y) { if(x < y) { x = y ; return true ;} return false;}
template <class T> bool mini(T &x, T y) { if(x > y) { x = y ; return true ;} return false;}


const int N = 1e5 + 2;

int n, h[N], w[N];
void inp()
{
    cin >> n;
    FOR(i, 1, n) cin >> h[i];
    FOR(i, 1, n) cin >> w[i];
}

/* Try your best
    No regrets */

namespace subtask_1
{

    ll sq(ll x)
    {
        return 1LL * x * x;
    }

    ll dp[N];
    void slv()
    {
        memset(dp, 0x3f, sizeof dp);
        dp[1] = 0;
        FOR(i, 2, n) {
            ll total = 0;
            FORD(j, i - 1, 1) {
                mini(dp[i], dp[j] + sq(h[i] - h[j]) + total);
                total += w[j];
            }
        }
        cout << dp[n];
    }
}

namespace subtask_2
{
    const long long INF = 1e18;

    const int MAX = 1e6 + 2;

    ll dp[N], sum[N];
    struct Line
    {
        ll a, b;
        Line() {a = 0, b = INF;}
        Line(ll _a, ll _b) {a = _a, b = _b;}
        ll operator()(ll x) {return a * x + b;}
    } st[4 * MAX];

    void upd(int id, int l, int r, Line L)
    {
        if(l == r) {
            if(st[id](l) > L(l)) swap(st[id], L);
            return;
        }
        int mid = (r + l) >> 1;
        if(st[id].a > L.a) swap(st[id], L);
        if(st[id](mid) > L(mid)) {
            swap(st[id], L);
            upd(id << 1 | 1, mid + 1, r, L);
        }
        else upd(id << 1, l, mid, L);
    }
    ll get(int id, int l, int r, int pos)
    {
        if(l == r) return st[id](pos);
        int mid = (r + l) >> 1;
        if(pos <= mid) return min(st[id](pos), get(id << 1, l, mid, pos));
        else return get(id << 1 | 1, mid + 1, r, pos);
    }
    void slv()
    {
        FOR(i, 1, n) {
            sum[i] = sum[i - 1] + w[i];
        }

        dp[1] = 0;
        upd(1, 1, 1e6, Line(- 2 * h[1], dp[1] + 1LL * h[1] * h[1] - sum[1]));
        FOR(i, 2, n) {
            dp[i] = get(1, 1, 1e6, h[i]) + 1LL * h[i] * h[i] +  sum[i] - w[i];
            upd(1, 1, 1e6, Line(- 2 * h[i], dp[i] + 1LL * h[i] * h[i] - sum[i]));
        }
        cout << dp[n];
    }
}

/* Code slowly, think carefully */

main()
{
    ios_base::sync_with_stdio(0);cin.tie(0);cout.tie(0);

    #define __Azul__ "CEOI17_building"
    if(fopen(__Azul__".inp", "r")) {
        freopen(__Azul__".inp", "r", stdin);
        freopen(__Azul__".out", "w", stdout);
    }

    bool qs = 0;

    int T = 1;
    if(qs) cin >> T;
    while(T--) {
        inp();
//        subtask_2::slv(); return 0;
        if(n <= 1000) subtask_1::slv();
        else subtask_2::slv();
    }

    cerr << "\nTime" << 0.001 * clock() << "s "; return 0;


}

컴파일 시 표준 에러 (stderr) 메시지

building.cpp:111:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  111 | main()
      | ^~~~
building.cpp: In function 'int main()':
building.cpp:117:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  117 |         freopen(__Azul__".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~
building.cpp:118:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  118 |         freopen(__Azul__".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 30 / 30
• Subtask 2: 0 / 30
• Subtask 3: 0 / 40