提出 #29757086

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ソースコード 拡げる

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

#define rep(i, a, b) for(int i = (a); i < (b); ++i)
#define per(i, a, b) for(int i = (b)-1; i >= (a); --i)
#define all(x) begin(x), end(x)
#define sz(x) (int)(x).size()
#define pb push_back
#define eb emplace_back
#define mp make_pair
#define fst first
#define snd second

template<class T> bool ckmin(T& a, const T& b) { return b < a ? a = b, 1 : 0; }
template<class T> bool ckmax(T& a, const T& b) { return a < b ? a = b, 1 : 0; }

typedef long long ll;
typedef long double ld;
typedef pair<int, int> pii;
typedef vector<int> vi;
typedef vector<vi> vvi;
typedef vector<ll> vl;
typedef vector<vl> vvl;
typedef vector<pii> vii;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

int main() {
  cin.tie(0)->sync_with_stdio(0);
  cin.exceptions(cin.failbit);

  int n;
  cin >> n;

  vl a(n);
  rep(i,0,n) cin >> a[i];

  ll omx = *max_element(all(a));
  ll mx = 0;
  ll ans = 0;

  rep(i,0,n) {
    int l = (i+n-1)%n;
    int r = (i+1) % n;
    ll tot = max(0ll, a[i] - a[l] - a[r]);
    if (l == r) tot = 0;
    ans += tot;
    ckmax(mx, a[i] - tot);
  }

  ans += mx;
  if (n < 5 && ans > omx) ans = omx;

  cout << ans << '\n';
}

提出情報

ジャッジ結果