Submission #1088846

#	Time	Username	Problem	Language	Result	Execution time	Memory
1088846		Khanhcsp2	K blocks (IZhO14_blocks)	C++14	53 / 100	4 ms	3164 KiB

blocks

#include<bits/stdc++.h>
#define el '\n'
#define fi first
#define sc second
#define int ll
#define pii pair<int, int>
#define all(v) v.begin(), v.end()
using namespace std;
using ll=long long;
using ull=unsigned long long;
using ld=long double;
const int mod=1e9+7;
const int N=1e5+11;
int n, a[N], k, dp[101][N], l[N], bit[20][N];
vector<int> dp1, dp2;
void sub1()
{
    for(int i=1;i<=k;i++) for(int j=1;j<=n;j++) dp[i][j]=1e18;
    int mx=0;
    for(int i=1;i<=n;i++)
    {
        mx=max(mx, a[i]);
        dp[1][i]=mx;
    }
    for(int i=2;i<=k;i++)
    {
        for(int j=1;j<=n;j++)
        {
            int mx=0;
            for(int o=j;o>=i;o--)
            {
                mx=max(mx, a[o]);
                dp[i][j]=min(dp[i][j], dp[i-1][o-1]+mx);
            }
        }
    }
    cout << dp[k][n];
}
void build()
{
    for(int i=1;i<=n;i++) bit[0][i]=a[i];
    for(int j=1;j<=18;j++)
    {
        for(int i=1;i+(1<<j)-1<=n;i++)
        {
            bit[j][i]=max(bit[j-1][i], bit[j-1][i+(1<<(j-1))]);
        }
    }
}
int calc(int l, int r)
{
    int k=__lg(r-l+1);
    return max(bit[k][l], bit[k][r-(1<<k)+1]);
}
void dnc(int l, int r, int lll, int rrr)
{
    if(l>r) return;
    int mid=(l+r)/2;
    pii s= {1e18, -1};
    for(int i=lll; i<=max(mid, rrr); i++) s=min(s, {dp1[i]+calc(i+1, mid),i});
    dp2[mid]=s.fi;
    int opt=s.sc;
    dnc(l, mid-1, lll, opt);
    dnc(mid+1, r, opt, rrr);
}
void sub2()
{
    dp1.assign(n+1, 1e16);
    dp1[0]=0;
    dp2.resize(n+1, 1e16);
    dp2[0]=0;
    for(int i=1; i<=k; i++)
    {
        dnc(i, n, i-1, n-1);
        for(int j=1; j<=n; j++) dp1[j]=dp2[j], dp2[j]=1e16;
    }
    cout << dp1[n];
}
void sol()
{
    cin >> n >> k;
    for(int i=1;i<=n;i++) cin >> a[i];
    build();
    if(n<=100) sub1();
    else sub2();
//    sub2();
}
signed main()
{
//    freopen("divisor.INP", "r", stdin);
//    freopen("divisor.OUT", "w", stdout);
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int t=1;
    //cin >> t;
    while(t--)
    {
        sol();
    }
}

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