Submission #1571408

---

Source Code Expand

#include <cstdio>
#include <cassert>
#include <cmath>
#include <cstring>

#include <iostream>
#include <algorithm>
#include <vector>
#include <map>
#include <set>
#include <functional>
#include <stack>
#include <queue>

#include <tuple>

#define getchar getchar_unlocked
#define putchar putchar_unlocked

#define _rep(_1, _2, _3, _4, name, ...) name
#define rep2(i, n) rep3(i, 0, n)
#define rep3(i, a, b) rep4(i, a, b, 1)
#define rep4(i, a, b, c) for (int i = int(a); i < int(b); i += int(c))
#define rep(...) _rep(__VA_ARGS__, rep4, rep3, rep2, _)(__VA_ARGS__)

using namespace std;

using i64 = long long;
using u8 = unsigned char;
using u32 = unsigned;
using u64 = unsigned long long;
using f80 = long double;

i64 get_i64() {
  int c; i64 n;
  while ((c = getchar()) < '0');
  n = c - '0';
  while ((c = getchar()) >= '0') n = n * 10 + (c - '0');
  return n;
}

template <typename T>
__attribute__((target("avx"), optimize("-O3")))
i64 optimal_alphabetic_tree(const vector<T>& A) {
  constexpr T Inf = T(1) << (sizeof(T) * 8 - 2);
  int N = A.size();
  vector<T> S(N + 2);
  S[0] = S[N + 1] = Inf;
  for (int i = 1; i <= N; ++i) S[i] = A[i - 1];
  i64 ret = 0;
  int first = 1;
  while (N > 1) {
    for (int i = first; i < N; ++i) if (S[i - 1] > S[i + 1] && S[i] <= S[i + 2]) {
      T w = S[i] + S[i + 1]; ret += w;
      for (int j = i + 1; j <= N; ++j) S[j] = S[j + 1];
      for (int j = i - 1; j >= 0; --j) {
        if (S[j] < w) S[j + 1] = S[j];
        else { S[j + 1] = w; first = max(1, j - 1); break; }
      }
      --N; break;
    }
  }
  return ret;
}

void solve() {
  int N;
  while (~scanf("%d", &N)) {
    vector<i64> A(N); rep(i, N) A[i] = get_i64();
    printf("%llu\n", optimal_alphabetic_tree<i64>(A));
  }
}

int main() {
  clock_t beg = clock();
  solve();
  clock_t end = clock();
  fprintf(stderr, "%.3f sec\n", double(end - beg) / CLOCKS_PER_SEC);
  return 0;
}

Submission Info

Judge Result