Submission #855311

#	Time	Username	Problem	Language	Result	Execution time	Memory
855311		vjudge1	Split the sequence (APIO14_sequence)	C++17	28 / 100	2060 ms	98396 KiB

sequence

//Bismillahir-Rahmanir-Rahim

#include <bits/stdc++.h>
#pragma comment(linker, "/stack:200000000")
#pragma GCC optimize("Ofast")
#pragma GCC target("sse,sse2,sse3,ssse3,sse4,popcnt,abm,mmx,avx,avx2,tune=native")

#define pb push_back
#define pii pair <int, int>
#define pll pair <long long, long long>
#define pld pair <long double, long double>
#define ll long long
#define ld long double
#define x first
#define y second
#define all(v) v.begin(),v.end()
#define sz(s) (int)s.size()
#define skip continue
#define bpop(x) (ll)__builtin_popcountll(x)

using namespace std;

const int N = 1e3 + 7;
const int M = 1e2 + 7;
const int MAXA = 5e4 + 7;
const int inf = 1e18 + 7;
const ll INF = 1e18 + 7;
const ll MOD = 1e9 + 7;

pii dir[] = {{0, 1}, {1, 0}, {0, -1}, {-1, 0}};

#define int long long

//mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

int n, k, a[N], pre[N];
int calc(int l, int r) {
    return pre[r] - pre[l - 1];
}
pii pr[52][52][52];
void go(int l, int r, int i) {
    if (i <= 1 || !l || !r)return;
    int mid, j;
    tie(mid, j) = pr[l][r][i];
    go(l, mid, j);
    cout << mid << ' ';
    go(mid + 1, r, i - j);
}
void subtask12() {
    bool ok[52][52][52];
    int dp[52][52][52];
    memset(dp, 0, sizeof dp), memset(ok, 0, sizeof ok);
    for (int l = 1;l <= n;l++) {
        for (int r = l;r <= n;r++)ok[l][r][1] = 1;
    }
    for (int len = 2;len <= n;len++) {
        for (int l = 1;l <= n - len + 1;l++) {
            int r = l + len - 1;
            for (int mid = l;mid < r;mid++) {
                int prod = calc(l, mid) * calc(mid + 1, r);
                for (int i = 2;i <= k + 1;i++) {
                    for (int j = 1;j < i;j++) {
                        if (ok[l][mid][j] && ok[mid + 1][r][i - j]) {
                            int cost = dp[l][mid][j] + dp[mid + 1][r][i - j] + prod;
                            if (cost > dp[l][r][i])dp[l][r][i] = cost, pr[l][r][i] = {mid, j};
                            ok[l][r][i] = 1;
                            //cout << l << ' ' << r << ' ' << i << ':' << dp[l][r][i] << '\n';
                        }
                    }
                }
            }
        }
    }
    cout << dp[1][n][k + 1] << '\n';
    go(1, n, k + 1);
}
void subtask34() {
    int dp[N][N], pr[N][N];
    memset(dp, 0, sizeof dp), memset(pr, 0, sizeof pr);
    for (int i = 2;i <= n;i++) {
        for (int last = 1;last < i;last++) {
            for (int j = 2;j <= k + 1;j++) {
                int x = dp[last][j - 1] + pre[last] * (pre[i] - pre[last]);
                if (x > dp[i][j])dp[i][j] = x, pr[i][j] = last;
            }
        }
    }
    int ans = dp[n][k + 1];
    cout << ans << '\n';
    int pos = n, cur = k + 1;
    vector <int> path;
    while (cur > 0) {
        pos = pr[pos][cur], cur--;
        if (pos)path.pb(pos);
    }
    reverse(all(path));
    for (auto to : path)cout << to << ' ';
}
void greedy() {
    set <pii> segments;
    segments.insert({1, n});
    int ans = 0;
    vector <int> took;
    for (int t = 1;t <= k;t++) {
        pii chose;
        int mx = 0, pos = 0;
        for (auto p : segments) {
            int l = p.x, r = p.y;
            for (int i = l;i < r;i++) {
                int prod = calc(l, i) * calc(i + 1, r);
                if (prod > mx)mx = prod, chose = p, pos = i;
            }
        }
        ans += mx;
        int l, r;
        tie(l, r) = chose;
        segments.erase(chose), segments.insert({l, pos}), segments.insert({pos + 1, r});
        took.pb(pos);
    }
    cout << ans << '\n';
    sort(all(took));
    for (auto to : took)cout << to << ' ';
}
void solve() {
    cin >> n >> k;
    for (int i = 1;i <= n;i++)cin >> a[i], pre[i] = pre[i - 1] + a[i];
    if (n <= 50)subtask12();
    else subtask34();
}
signed main() {
    //srand(time(NULL));
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    //freopen("milkorder.in", "r", stdin);
    //freopen("milkorder.out", "w", stdout);
    int test = 1;
    //cin >> test;
    for (int i = 1;i <= test;i++) {
        //cout << "Case " << i << ": ";
        solve();
    }
    return 0;
}

Compilation message (stderr)

sequence.cpp:4: warning: ignoring '#pragma comment ' [-Wunknown-pragmas]
    4 | #pragma comment(linker, "/stack:200000000")
      | 
sequence.cpp:26:22: warning: overflow in conversion from 'double' to 'int' changes value from '1.0e+18' to '2147483647' [-Woverflow]
   26 | const int inf = 1e18 + 7;
      |                 ~~~~~^~~

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