记录编号 602784 评测结果 AAAAAAA
题目名称 106.[NOIP 2003]加分二叉树 最终得分 100
用户昵称 GravatarLikableP 是否通过 通过
代码语言 C++ 运行时间 0.011 s
提交时间 2025-07-05 17:15:36 内存使用 1.45 MiB
显示代码纯文本
#include <algorithm>
#include <cstdio>

template <typename T> T read();
template <typename T> void write(T, char);
void dfs(int, int);

int n;
int a[50];
int f[50][50], root[50][50];

int main() {
  freopen("jfecs.in", "r", stdin);
  freopen("jfecs.out", "w", stdout);
  n = read<int>();
  ::std::fill(f[0], f[0] + 2500 - 1, 1);
  for (int i = 1; i <= n; ++i) f[i][i] = a[i] = read<int>(), root[i][i] = i;

  for (int len = 2; len <= n; ++len) {
    for (int l = 1; l <= n - len + 1; ++l) {
      int r = l + len - 1;
      for (int k = l; k <= r; ++k) {
        int data = f[l][k - 1] * f[k + 1][r] + a[k];
        if (f[l][r] < data) f[l][r] = data, root[l][r] = k;
      }
    }
  }

  write(f[1][n], '\n');
  dfs(1, n);
  return 0;
}

void dfs(int l, int r) {
  if (!root[l][r]) return;
  write(root[l][r], ' ');
  dfs(l, root[l][r] - 1), dfs(root[l][r] + 1, r);
}

#define isdigit(ch) ((ch) >= '0' && (ch) <= '9')
template <typename T> T read() {
  T res = 0, f = 1;
  char ch = getchar();
  for (; !isdigit(ch); ch = getchar())
    if (ch == '-') f = -1;
  for (; isdigit(ch); ch = getchar()) res = (res << 3) + (res << 1) + (ch ^ 48);
  return res * f;
}

template <typename T> void write(T x, char ed) {
  if (x < 0) x = -x, putchar('-');
  static int sta[sizeof(T) << 2], top = 0;
  do {
    sta[++top] = x % 10;
    x /= 10;
  } while (x);
  while (top) {
    putchar(sta[top--] ^ 48);
  }
  putchar(ed);
}