Submission #948129

#	Time	Username	Problem	Language	Result	Execution time	Memory
948129		steveonalex	Split the sequence (APIO14_sequence)	C++11	100 / 100	992 ms	83040 KiB

sequence

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef unsigned long long ull;
 
#define MASK(i) (1ULL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()
 
ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}
 
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ll mask){return __builtin_popcountll(mask);}
int ctz(ll mask){return __builtin_ctzll(mask);}
int logOf(ll mask){return 63 - __builtin_clzll(mask);}
 
mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}
 
template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }
 
template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }
 
template <class T>
    void printArr(T& container, string separator = " ", string finish = "\n", ostream &out = cout){
        for(auto item: container) out << item << separator;
        out << finish;
    }
 
template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }
 
const int N = 1e5 + 69, K = 202;
const ll INF = 1e18 + 69;
ll a[N], pref[N];
ll dp[2][N];
int trace[K][N];

void dnc(int layer, int l, int r, int optL, int optR){
    if (l > r) return;
    int mid = (l + r) >> 1;
    int opt = -1;
    for(int i = optL; i <= min(mid, optR); ++i){
        ll s1 = pref[mid] - pref[i-1], s2 = pref[i-1];
        if (maximize(dp[1][mid], dp[0][i-1] + s1 * s2)) opt = i;
    }
    trace[layer][mid] = opt - 1;
    dnc(layer, l, mid - 1, optL, opt);
    dnc(layer, mid + 1, r, opt, optR);

}
 
int main(void){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);
 
    int n, k; cin >> n >> k;
    for(int i = 1; i<=n; ++i) cin >> a[i];
    for(int i = 1; i<=n; ++i) pref[i] = pref[i-1] + a[i];
 
    for(int layer=  0; layer <= 1; ++layer) 
    for(int i = 0; i<=n; ++i) dp[layer][i] = -INF;
 
    dp[0][0] = 0;
    for(int layer = 1; layer <= k+1; ++layer){
        dnc(layer, layer, n, layer, n);
        for(int i = 0; i<=n; ++i){
            dp[0][i] = dp[1][i];
            dp[1][i] = -INF;
        }
    }
 
    cout << dp[0][n] << "\n";
 
    int i = n;
    for(int layer = k + 1; layer >= 2; --layer){
        cout << trace[layer][i] << " ";
        i = trace[layer][i];
    }
    cout << "\n";
 
    return 0;
}

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