Submission #989755

#	Time	Username	Problem	Language	Result	Execution time	Memory
989755		_shr104	Split the sequence (APIO14_sequence)	C++17	100 / 100	907 ms	84956 KiB

sequence

#include <bits/stdc++.h>
using namespace std;
typedef long long int ll;
typedef long double ld;
#define pb push_back
#define pf push_front
#define fi first
#define se second
const ll mod = 1e9+7, mxn = 1e5+7;
ll dp[mxn], old_dp[mxn], sum = 0, all_pair = 0, ans = 0, pfs_2[mxn];
int n, k, trace[mxn][207], a[mxn], pfs[mxn];
ll get(int l, int r)
{
    ll ansx = ((ll)pfs[r]-pfs[l-1])*((ll)pfs[r]-pfs[l-1])-pfs_2[r]+pfs_2[l-1];
    return ansx>>1;
}
void dnc(int j, int l, int r, int opt_l, int opt_r)
{
    int m = (r+l)>>1;
    pair<ll,int> res = {1e18, opt_l};
    for (int i = min(m,opt_r); i >= opt_l; i--) 
    {
        ll c = old_dp[i-1]+get(i,m);
        if (res.fi > c) {res = {c,i};}
    }
    dp[m] = res.fi; trace[m][j] = res.se;
    if (l <= m-1) dnc(j,l,m-1,opt_l,res.se); 
    if (m+1 <= r) dnc(j,m+1,r,res.se,opt_r);
}   
signed main()
{
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    // freopen("test.inp","r",stdin); freopen("test.out","w",stdout); freopen("test.err","w",stderr);
    cin >> n >> k; k++;
    for (int i = 1; i <= n; i++)
    {
        cin >> a[i];
        pfs[i] = pfs[i-1]+a[i];
        pfs_2[i] = pfs_2[i-1]+a[i]*a[i];  
    }
    for (int i = 1; i <= n; i++) {dp[i] = get(1,i);}
    for (int i = 2; i <= k; i++) 
    {
        for (ll j = 1; j <= n; j++) old_dp[j] = dp[j];
        dnc(i,1,n,1,n);
    }
    cout << get(1,n)-dp[n] << '\n';
    vector<int> v;
    while (k > 1) 
    {
        v.pb(trace[n][k]-1);    
        n = trace[n][k]-1; 
        k--;
    }
    reverse(v.begin(),v.end());
    for (int i : v) cout << i << ' ';
}

• Subtask 1: 11 / 11
• Subtask 2: 11 / 11
• Subtask 3: 11 / 11
• Subtask 4: 17 / 17
• Subtask 5: 21 / 21
• Subtask 6: 29 / 29