Submission #989478

#	Time	Username	Problem	Language	Result	Execution time	Memory
989478		_shr104	Split the sequence (APIO14_sequence)	C++17	49 / 100	145 ms	131072 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 n, k, dp[mxn][207], trace[mxn][207], a[mxn], sum = 0, all_pair = 0, ans = 0, mo_l = 1, mo_r = 0; 
void add(ll i) 
{
    ans += sum*a[i];
    sum += a[i];
}
void rmv(ll i) 
{
    ans -= a[i]*(sum-a[i]);
    sum -= a[i];
}
ll get(ll l, ll r)
{
    while (mo_l < l) rmv(mo_l++);
    while (mo_l > l) add(--mo_l);
    while (mo_r < r) add(++mo_r);
    while (mo_r > r) rmv(mo_r--);
    return ans;
}
vector<vector<ll>> opt;
void dnc(ll j, ll l, ll r, ll opt_l, ll opt_r)
{
    ll m = (r+l)>>1;
    pair<ll,ll> res = {1e18, opt_l};
    for (ll i = opt_l; i <= min(m,opt_r); i++) res = min(res,{dp[i-1][j-1]+get(i,m),i});
    dp[m][j] = 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; ll sx = 0; k++;
    for (ll i = 1; i <= n; i++)
    {
        cin >> a[i];
        all_pair += sx*a[i];
        sx += a[i];   
    }
    for (ll i = 1; i <= n; i++) {dp[i][1] = get(1,i); trace[i][1] = 2;}
    for (ll i = 2; i <= k; i++) dnc(i,1,n,1,n);
    cout << all_pair-dp[n][k] << '\n';
    vector<ll> v;
    while (k > 1) 
    {
        v.pb(trace[n][k]-1);
        n = trace[n][k]-1; 
        k--;
    }
    reverse(v.begin(),v.end());
    for (ll i : v) cout << i << ' ';
}

• Subtask 1: 0 / 11
• Subtask 2: 11 / 11
• Subtask 3: 0 / 11
• Subtask 4: 17 / 17
• Subtask 5: 21 / 21
• Subtask 6: 0 / 29