제출 #477124

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
477124		LptN21	Building Bridges (CEOI17_building)	C++14	100 / 100	130 ms	128556 KiB

building

#include <bits/stdc++.h>
using namespace std;
#define fastIO ios_base::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL)
#define PI acos(-1.0)
#define FF first
#define SS second
#define eps 1e-9
// vector
#define pb push_back
#define sz(v) int((v).size())
#define all(v) (v).begin(), (v).end()
#define lb lower_bound
#define ub upper_bound
// bit
#define CNTBIT(x) __builtin_popcount(x)
#define ODDBIT(x) __builtin_parity(x)
#define MASK(i) (1ll<<(i))
#define BIT(x, i) (((x)>>(i))&1)
#define SUBSET(big, small) (((big)&(small))==(small))
#define MINBIT(x) (x)&(-x)
// typedef
typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;
typedef pair<ll, ll> ii;
typedef pair<int, ii> i3;
/* CODE BELOW */
const int N=2e6+7, M=1e5+7;
const int MOD=1e9+7;
const ll oo=1e9+9;

int n, m, k, t;

int a[M];
ll p[M], _dp[M];

const ll _oo=1e17+9;

struct Line {
    ll m, b;
    Line() {m=oo;
        b=_oo;
    }
    Line(ll _m, ll _b) {
        m=_m, b=_b;
    }
    ll operator()(ll x) { return m * x + b; }
} st[N<<2];

void insert(int l, int r, Line seg, int o=0) {
  if(l + 1 == r) {
    if(seg(l) < st[o](l)) st[o] = seg;
    return;
  }
  int mid= (l + r) >> 1, lson = o * 2 + 1, rson = o * 2 + 2;
  if(st[o].m < seg.m) swap(st[o], seg);
  if(st[o](mid) > seg(mid)) {
    swap(st[o], seg);
    insert(l, mid, seg, lson);
  } else insert(mid, r, seg, rson);
}
ll query(int l, int r, int x, int o=0) {
  if(l + 1 == r) return st[o](x);
  int mid = (l + r) >> 1, lson = o * 2 + 1, rson = o * 2 + 2;
  if(x < mid) return min(st[o](x), query(l, mid, x, lson));
  else return min(st[o](x), query(mid, r, x, rson));
}

signed main() {
    //freopen("test.inp", "r", stdin);
    //freopen("test.out", "w", stdout);
    //fastIO;
    scanf("%d", &n);
    for(int i=1;i<=n;i++) scanf("%d", &a[i]);
    for(int i=1;i<=n;i++) {
        scanf("%d", &m);
        p[i]=p[i-1]+m;
    }

    _dp[1]=0;
    const int SUB1=1000;
    #define sqr(x) 1LL*(x)*(x)

    if(n<=SUB1) {
        for(int i=2;i<=n;i++) {
            _dp[i]=oo;
            for(int j=i-1;j>0;j--) {
                ll cost=sqr(a[i]-a[j])+p[i-1]-p[j];
                _dp[i]=min(_dp[i], _dp[j]+cost);
            }
        }
        printf("%lld", _dp[n]);
    } else {
        insert(1, N, {-2*a[1], sqr(a[1])-p[1]});
        for(int i=2;i<=n;i++) {
            _dp[i]=sqr(a[i])+query(1, N, a[i])+p[i-1];
            insert(1, N, {-2*a[i], _dp[i]+sqr(a[i])-p[i]});
            //printf("%d %lld %lld _ %lld\n", i, _dp[i], query(1, N, a[i]), _dp[i]+p[i]);
        }
        printf("%lld", _dp[n]);
    }

    return 0;
}
/* stuff you should look for
    - int overflow, array bounds
    - special/edge cases (n=1?)
    - do smth instead of nothing and stay organized
    - WRITE STUFF DOWN
    - DONT JUST STICK ON ONE APPROACH
*/

컴파일 시 표준 에러 (stderr) 메시지

building.cpp: In function 'int main()':
building.cpp:73:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   73 |     scanf("%d", &n);
      |     ~~~~~^~~~~~~~~~
building.cpp:74:32: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   74 |     for(int i=1;i<=n;i++) scanf("%d", &a[i]);
      |                           ~~~~~^~~~~~~~~~~~~
building.cpp:76:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   76 |         scanf("%d", &m);
      |         ~~~~~^~~~~~~~~~

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