oj.uz

Submission #335073

# Submission time Handle Problem Language Result Execution time Memory
335073 2020-12-11T05:16:54 Z VROOM_VARUN K blocks (IZhO14_blocks) C++14
0 / 100
 27 ms 40812 KB 
/*
ID: varunra2
LANG: C++
TASK: kblocks
*/

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

#ifdef DEBUG
#include "lib/debug.h"
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#define debug_arr(...) \
  cerr << "[" << #__VA_ARGS__ << "]:", debug_arr(__VA_ARGS__)
#pragma GCC diagnostic ignored "-Wsign-compare"
//#pragma GCC diagnostic ignored "-Wunused-parameter"
//#pragma GCC diagnostic ignored "-Wunused-variable"
#else
#define debug(...) 42
#endif

#define EPS 1e-9
#define IN(A, B, C) assert(B <= A && A <= C)
#define INF (int)1e9
#define MEM(a, b) memset(a, (b), sizeof(a))
#define MOD 1000000007
#define MP make_pair
#define PB push_back
#define all(cont) cont.begin(), cont.end()
#define rall(cont) cont.end(), cont.begin()
#define x first
#define y second

const double PI = acos(-1.0);
typedef long long ll;
typedef long double ld;
typedef pair<int, int> PII;
typedef map<int, int> MPII;
typedef multiset<int> MSETI;
typedef set<int> SETI;
typedef set<string> SETS;
typedef vector<int> VI;
typedef vector<PII> VII;
typedef vector<VI> VVI;
typedef vector<string> VS;

#define rep(i, a, b) for (int i = a; i < (b); ++i)
#define trav(a, x) for (auto& a : x)
#define sz(x) (int)(x).size()
typedef pair<int, int> pii;
typedef vector<int> vi;
#pragma GCC diagnostic ignored "-Wsign-compare"
// util functions

int n, k;

VI vals;

int curk = 0;
const int MAXN = 1e5 + 2;
const int K = 20;
const int MAXK = 102;
int lg2[MAXN + 1];
int dp[MAXK][MAXN] = {};

void init() {
  vals.resize(n);
  lg2[1] = 0;
  for (int i = 2; i <= MAXN; i++) lg2[i] = lg2[i / 2] + 1;
}

int st[MAXN][K + 1];

void calc(int ind) {
  for (int i = 0; i < n; i++) st[i][0] = dp[ind][i];

  for (int j = 1; j <= K; j++)
    for (int i = 0; i + (1 << j) <= n; i++)
      st[i][j] = min(st[i][j - 1], st[i + (1 << (j - 1))][j - 1]);
}

int qry(int L, int R) {
  int j = lg2[R - L + 1];
  L = max(L, 0);
  if (R < L) return 0;
  return min(st[L][j], st[R - (1 << j) + 1][j]);
}

// can we do dnc opt :eyes:
// oops we can't :sadge:
// we can solve using segment tree, but im worried it will tle
// rmq it is lmao
 
int main() {
  // #ifndef ONLINE_JUDGE
  // freopen("kblocks.in", "r", stdin);
  // freopen("kblocks.out", "w", stdout);
  // #endif
  cin.sync_with_stdio(0);
  cin.tie(0);

  cin >> n >> k;

  init();

  for (int i = 0; i < n; i++) {
    cin >> vals[i];
  }

  VI lft(n, 0);

  rep(i, 0, MAXK) rep(j, 0, MAXN) dp[i][j] = INF;

  stack<int> st;

  for (int i = 0; i < n; i++) {
    while (!st.empty() and vals[st.top()] <= vals[i]) st.pop();
    if (st.empty())
      lft[i] = -1;
    else
      lft[i] = st.top();
    st.push(i);
  }

  for (int i = 0; i < k; i++) {
    for (int j = 0; j < n; j++) {
      dp[i][j] = qry(lft[j], j - 1) + vals[j];
      if (lft[j] != -1) dp[i][j] = min(dp[i][j], dp[i][lft[j]]);
    }
    calc(i);
  }

  cout << dp[k - 1][n - 1] << '\n';

  return 0;
}

Subtask #1
0 / 14.0

# Verdict Execution time Memory Grader output
1 Correct 26 ms 40684 KB Output is correct
2 Incorrect 26 ms 40684 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #2
0 / 18.0

# Verdict Execution time Memory Grader output
1 Correct 27 ms 40812 KB Output is correct
2 Incorrect 25 ms 40684 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #3
0 / 21.0

# Verdict Execution time Memory Grader output
1 Correct 26 ms 40684 KB Output is correct
2 Incorrect 26 ms 40684 KB Output isn't correct
3 Halted 0 ms 0 KB -

Subtask #4
0 / 47.0

# Verdict Execution time Memory Grader output
1 Correct 26 ms 40684 KB Output is correct
2 Incorrect 26 ms 40684 KB Output isn't correct
3 Halted 0 ms 0 KB -