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답안 #476246

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
476246 2021-09-25T15:23:34 Z LptN21 Building Bridges (CEOI17_building) C++14
60 / 100
 102 ms 64452 KB 
#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=1e6+7, M=1e5+7;
const int MOD=1e9+7;
const ll oo=1e9+9;

int n, m, k, t;

int a[M], p[M];
ll _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])-(p[i]-p[i-1])+query(1, N, a[i]);
            insert(1, N, {-2*a[i], _dp[i]+sqr(a[i])});
            //printf("%d %lld %lld _ %lld\n", i, _dp[i], query(1, N, a[i]), _dp[i]+p[i]);
        }
        printf("%lld", _dp[n]+p[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
*/

Compilation message

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
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 29 ms 62984 KB Output is correct
2 Correct 30 ms 62864 KB Output is correct
3 Correct 31 ms 62876 KB Output is correct
4 Correct 29 ms 62904 KB Output is correct
5 Correct 30 ms 62924 KB Output is correct

Subtask #2
30.0 / 30.0

# 결과 실행 시간 메모리 Grader output
1 Correct 78 ms 64392 KB Output is correct
2 Correct 78 ms 64396 KB Output is correct
3 Correct 80 ms 64452 KB Output is correct
4 Correct 72 ms 64380 KB Output is correct
5 Correct 66 ms 64372 KB Output is correct

Subtask #3
0 / 40.0

# 결과 실행 시간 메모리 Grader output
1 Correct 29 ms 62984 KB Output is correct
2 Correct 30 ms 62864 KB Output is correct
3 Correct 31 ms 62876 KB Output is correct
4 Correct 29 ms 62904 KB Output is correct
5 Correct 30 ms 62924 KB Output is correct
6 Correct 78 ms 64392 KB Output is correct
7 Correct 78 ms 64396 KB Output is correct
8 Correct 80 ms 64452 KB Output is correct
9 Correct 72 ms 64380 KB Output is correct
10 Correct 66 ms 64372 KB Output is correct
11 Correct 81 ms 64348 KB Output is correct
12 Correct 101 ms 64392 KB Output is correct
13 Correct 78 ms 64380 KB Output is correct
14 Correct 102 ms 64344 KB Output is correct
15 Correct 72 ms 64404 KB Output is correct
16 Correct 72 ms 64404 KB Output is correct
17 Incorrect 62 ms 64380 KB Output isn't correct
18 Halted 0 ms 0 KB -