Submission #671806

#	Time	Username	Problem	Language	Result	Execution time	Memory
671806		Alihan_8	K blocks (IZhO14_blocks)	C++17	0 / 100	1 ms	324 KiB

blocks

#include <bits/stdc++.h>
// include <ext/pb_ds/assoc_container.hpp>
// include <ext/pb_ds/tree_policy.hpp>
// using namespace __gnu_pbds;
using namespace std;
#define all(x) x.begin(), x.end()
#define pb push_back
// define ordered_set tree<int,null_type,less_equal<int>,rb_tree_tag,tree_order_statistics_node_update>
#define mpr make_pair
#define ln '\n'
void IO(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
#define int long long
signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);

    int n, k; cin >> n >> k;
    const int inf = 1e15;
    vector <int> p(n+1, inf);
    for ( int i = 1; i <= n; i++ ) cin >> p[i];
    vector <vector<int>> dp(k+1, vector <int> (n+1, inf));
    vector <int> f(n+1, inf);
    dp[0][0] = 0;
    auto chmin = [&](int &l, int r){l = min(l, r);};
    for ( int i = 1; i <= k; i++ ){
        stack <int> st;
        st.push(0);
        int Mx = -inf;
        for ( int j = 1; j <= n; j++ ){
            Mx = max(Mx, p[j]);
            if ( i == 1 ) dp[i][j] = Mx;
            while ( p[st.top()] <= p[j] ){
                int last = st.top(); st.pop();
                chmin(f[st.top()], f[last]);
            }
            chmin(dp[i][j], dp[i][st.top()]);
            chmin(dp[i][j], f[st.top()]+p[j]);
            st.push(j);
        }
        for ( int j = 1; j <= n; j++ ) f[j] = dp[i][j];
    }
    cout << dp[k].back();

    cout << '\n';
}

Compilation message (stderr)

blocks.cpp: In function 'void IO(std::string)':
blocks.cpp:11:29: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   11 | void IO(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
      |                      ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
blocks.cpp:11:70: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   11 | void IO(string name){freopen((name+".in").c_str(),"r",stdin); freopen((name+".out").c_str(),"w",stdout);}
      |                                                               ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

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