Submission #476193

#	Time	Username	Problem	Language	Result	Execution time	Memory
476193		Neos	Building Bridges (CEOI17_building)	C++14	60 / 100	312 ms	4628 KiB

building

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef long double ld;
typedef unsigned long long ull;
typedef pair<ll, ll> ii;
typedef vector<int> vi;
typedef vector<ll> vll;
typedef vector<ii> vii;
typedef vector<vi> vvi;
typedef vector<vll> vvll;
typedef vector<vii> vvii;
 
#define task "test"
#define fastIO ios::sync_with_stdio(false), cin.tie(NULL), cout.tie(NULL)
#define forw(i, l, r) for( ll i = (l) ; i < (r) ; i++ )
#define forb(i, r, l) for( ll i = (r) ; i >= (l) ; i-- )
#define sz(x) (int)x.size()
#define fi first
#define se second
#define all(x) x.begin(), x.end()
#define numBit(x) __builtin_popcount(x)
#define lb lower_bound
#define ub upper_bound
#define ar array
#define endl '\n'
 
const int dx[4] = {-1, 0, 1, 0};
const int dy[4] = {0, -1, 0, 1};
 
const int N = 2e5 + 7;
const ll inf = 1e18;

int n;
ll h[N], w[N], dp[N], totW = 0;

ll sqr(ll x) {
  return x * x;
}

int main() {
  // fastIO;

  scanf("%d", &n);
  forw(i, 1, n + 1) scanf("%lld", &h[i]);
  forw(i, 1, n + 1) scanf("%lld", &w[i]), totW += w[i];

  memset(dp, 0x3f, sizeof dp);
  if (n <= 1000) {
    dp[1] = -w[1];
    forw(i, 1, n + 1) forb(j, i - 1, 1) 
      dp[i] = min(dp[i], dp[j] + sqr(h[i] - h[j]) - w[i]);
    printf("%lld", dp[n] + totW);
  }
  else {
    ll ans = sqr(h[1] - h[n]) - w[1] - w[n] + totW;
    forw(W, -20, 21) {
      set<ll> s;
      forw(i, 2, n) {
        ll mid = (h[1] + h[i]) / 2;
        ans = min(ans, sqr(h[1] - h[i]) + sqr(h[n] - h[i]) - w[1] - w[i] - w[n] + totW);

        auto it = s.upper_bound(mid);
        if(it != s.end()) {
          ans = min(ans, sqr(h[i] - h[n]) + sqr(*it - h[1]) + sqr(h[i] - *it) - w[1] - w[i] - w[n] - W + totW);
        }

        it = s.upper_bound(mid);
        if(it != s.begin()) {
          --it;
          ans = min(ans, sqr(h[i] - h[n]) + sqr(*it - h[1]) + sqr(h[i] - *it) - w[1] - w[i] - w[n] - W + totW);
        }

        if (w[i] == W) s.insert(h[i]);
      }
    }
    printf("%lld", ans);
  }
}

/*
  Subtask 1: dp[i] = max(dp[j] + (hi - hj) ^ 2 + sum(w[i + 1]...w[j])
  Subtask 2: Chọn 2 cây cầu sao cho h[1] + sum(2, i - 1) + h[i] + sum(i + 1, j - 1) + h[j] + sum(j + 1, n - 1) + h[n] 
  
*/

Compilation message (stderr)

building.cpp: In function 'int main()':
building.cpp:46:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   46 |   scanf("%d", &n);
      |   ~~~~~^~~~~~~~~~
building.cpp:47:26: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   47 |   forw(i, 1, n + 1) scanf("%lld", &h[i]);
      |                     ~~~~~^~~~~~~~~~~~~~~
building.cpp:48:26: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   48 |   forw(i, 1, n + 1) scanf("%lld", &w[i]), totW += w[i];
      |                     ~~~~~^~~~~~~~~~~~~~~

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