Submission #932213

#	Time	Username	Problem	Language	Result	Execution time	Memory
932213		Xiaoyang	Split the sequence (APIO14_sequence)	C++17	0 / 100	49 ms	85076 KiB

sequence

#include<stdio.h>
int n, k, a[100010], sl[100010][210], j;
long long d[100010], dd[100010], s[100010];
void get_l(int st, int ed, int left, int right)
{
  int i, q, p;
  long long m=9e19, x;
  if(left > right) return;
  p=(left + right)/2;
  if(st == ed)
    {
      for(i = left; i<=right; ++i) sl[i][j]=st;
      return;
    }
    for(i = st; i <= ed; ++i)
    {
      x=d[i] + (s[p] - s[i])*(s[p] - s[i]);
      if (m > x){ m = x; q = i; }
    }
    sl[p][j]=q;
    get_l(st, q, left, p-1);
    get_l(q, ed, p + 1, right);
    return;
}
void back(int x, int dep){
  if (dep > 1)
  { 
    back(sl[x][dep], dep - 1); 
    printf("%d", sl[x][dep]);
  }
  return; 
}

int main()
{
  int i, l;
  scanf("%d%d", &n, &k);
  for(i=1; i<=n; ++i) scanf("%d", &a[i]);
  for(i=1; i<=n; ++i) s[i]=s[i-1]+a[i];
  for(i=1; i<=n; ++i) d[i]=s[i]*s[i];
  for(j=2; j<=k+1; ++j)
  {
    //
    get_l(j - 1, n-(k + 1 - j), j, n);
    for(i=j; i<=n; ++i)
      {
        l=sl[i][j];
        dd[i]=d[l] + (s[i] - s[l])*(s[i] - s[l]);
      }
      for(i = j; i <= n; ++i) d[i]=dd[i];
    }
  printf("%lld\n", (s[n] * s[n] - d[n])/2);
  back(n, k + 1);
}

Compilation message (stderr)

sequence.cpp: In function 'void get_l(int, int, int, int)':
sequence.cpp:8:15: warning: overflow in conversion from 'double' to 'long long int' changes value from '9.0e+19' to '9223372036854775807' [-Woverflow]
    8 |   long long m=9e19, x;
      |               ^~~~
sequence.cpp: In function 'int main()':
sequence.cpp:38:8: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   38 |   scanf("%d%d", &n, &k);
      |   ~~~~~^~~~~~~~~~~~~~~~
sequence.cpp:39:28: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   39 |   for(i=1; i<=n; ++i) scanf("%d", &a[i]);
      |                       ~~~~~^~~~~~~~~~~~~
sequence.cpp: In function 'void get_l(int, int, int, int)':
sequence.cpp:11:3: warning: 'q' may be used uninitialized in this function [-Wmaybe-uninitialized]
   11 |   if(st == ed)
      |   ^~

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