Submission #222931

#	Time	Username	Problem	Language	Result	Execution time	Memory
222931		Bruteforceman	Split the sequence (APIO14_sequence)	C++11	71 / 100	401 ms	131076 KiB

sequence

#include <bits/stdc++.h>
using namespace std;
int a[100010];
int n, k;
long long pre[100010];
long long dp[202][100010], opt[202][100010];
const long long inf = 1e17;
void solve(int row, int l, int r, int start, int fin) {
  if(l > r) return ;
  int mid = (l + r) >> 1;
  dp[row][mid] = -inf;
  for(int i = start; i <= fin; i++) {
    if(i >= mid) break;
    long long cost = dp[row - 1][i] + (pre[n] - pre[mid] + pre[i]) * (pre[mid] - pre[i]);
    if(cost > dp[row][mid]) {
      dp[row][mid] = cost;
      opt[row][mid] = i;
    }
  }
  solve(row, l, mid - 1, start, opt[row][mid]);
  solve(row, mid + 1, r, opt[row][mid], fin);
}
int main() {
  scanf("%d %d", &n, &k);
  k += 1;
  for(int i = 1; i <= n; i++) {
    scanf("%d", a + i);
  }
  for(int i = 1; i <= n; i++) {
    pre[i] = pre[i - 1] + a[i];
  }
  long long sum = pre[n];
  for(int j = 1; j <= n; j++) {
    dp[0][j] = -inf;
  }
  dp[0][0] = 0;
  for(int i = 1; i <= k; i++) {
    dp[i][0] = -inf;
    solve(i, 1, n, 0, n - 1);
  }
  printf("%lld\n", dp[k][n] / 2);
  int cur = n;
  int cnt = k;
  while(cnt) {
    cur = opt[cnt--][cur];
    if(cur) printf("%d ", cur);
  }
  puts("");
  return 0;
}

Compilation message (stderr)

sequence.cpp: In function 'int main()':
sequence.cpp:32:13: warning: unused variable 'sum' [-Wunused-variable]
   long long sum = pre[n];
             ^~~
sequence.cpp:24:8: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d %d", &n, &k);
   ~~~~~^~~~~~~~~~~~~~~~~
sequence.cpp:27:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d", a + i);
     ~~~~~^~~~~~~~~~~~~

• Subtask 1: 11 / 11
• Subtask 2: 11 / 11
• Subtask 3: 11 / 11
• Subtask 4: 17 / 17
• Subtask 5: 21 / 21
• Subtask 6: 0 / 29