Submission #336952

#	Time	Username	Problem	Language	Result	Execution time	Memory
336952		boykut	K blocks (IZhO14_blocks)	C++14	0 / 100	2 ms	492 KiB

blocks

#include <fstream>
#include <map>
#include <vector>
#include <stack>

using namespace std;

ifstream cin("triangles.in");
ofstream cout("triangles.out");

const int inf = 2e9;

int32_t main() {
  ios::sync_with_stdio(0);
  cin.tie(0);
  int N, K;
  cin >> N >> K;
  
  int dp[N][K];
  int a[N];
  
  for (int i = 1; i <= N; i++) {
    cin >> a[i];
  }
  
  for (int i = 0; i <= N; i++) {
    for (int j = 0; j <= K; j++) {
      dp[i][j] = inf;
    }
  }
  
  dp[0][0] = 0;
  dp[1][1] = a[1];
  for (int i = 2; i <= N; i++) {
    dp[i][1] = max(dp[i - 1][1], a[i]);
  }
  
  auto getmax = [&](int l, int r) -> int {
    int mx = a[l];
    for (int i = l; i <= r; i++) {
      mx = max(mx, a[i]);
    }
    return mx;
  };
  
  for (int k = 2; k <= K; k++) {
    stack < pair < int, int > > st;
    for (int i = 1; i <= N; i++) {
      int cur = dp[i - 1][k - 1];
      dp[i][k] = min(dp[i][k], cur + a[i]);
      
      while (!st.empty() && a[st.top().first] <= a[i]) {
        cur = min(cur,st.top().second);
        st.pop();
      }
      if (!st.empty())
        dp[i][k] = dp[st.top().first][k];
      
      st.push({i, cur});
    }
  }
  
  cout << dp[N][K] << '\n';
  
  return 0;
}

Compilation message (stderr)

blocks.cpp: In function 'int32_t main()':
blocks.cpp:38:8: warning: variable 'getmax' set but not used [-Wunused-but-set-variable]
   38 |   auto getmax = [&](int l, int r) -> int {
      |        ^~~~~~

• Subtask 1: 0 / 14
• Subtask 2: 0 / 18
• Subtask 3: 0 / 21
• Subtask 4: 0 / 47