Submission #700217

#	Time	Username	Problem	Language	Result	Execution time	Memory
700217		kioto2	K blocks (IZhO14_blocks)	C++14	100 / 100	227 ms	88720 KiB

blocks

#include<bits/stdc++.h>
#define fori(i,a,b) for(int i=a;i<=b;i++)
#define ford(i,a,b) for(int i=a;i>=b;i--)
#define int long long
using namespace std;
const int N=1e5+10;
int a[N],n,k,f[N][110];
int pre[110];
signed main()
{
    cin.tie(0)->ios_base::sync_with_stdio(0);
    if(fopen("task.inp","r"))
    {
        freopen("task.inp","r",stdin);
        freopen("task.out","w",stdout);
    }
    cin>>n>>k;
    fori(i,1,n) cin>>a[i];
    memset(f,50,sizeof(f));
    f[0][1]=0;
    fori(i,1,n) f[i][1]=max(f[i-1][1],a[i]);
    fori(j,2,k)
    {
        stack<pair<int,int>> st;
        fori(i,j,n)
        {
            int cur=f[i-1][j-1];
            while(!st.empty() && a[st.top().second]<=a[i])
            {
                cur=min(cur,st.top().first);
                st.pop();
            }
            f[i][j]=min(f[ (st.empty()?0:st.top().second) ][j],cur+a[i]);
            st.push({ cur,i });
        }
    }
    cout<<f[n][k];
}

Compilation message (stderr)

blocks.cpp: In function 'int main()':
blocks.cpp:14:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   14 |         freopen("task.inp","r",stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
blocks.cpp:15:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |         freopen("task.out","w",stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

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