Submission #699633

#	Time	Username	Problem	Language	Result	Execution time	Memory
699633		DennisTran	Feast (NOI19_feast)	C++17	71 / 100	262 ms	211824 KiB

feast

#pragma GCC optimize("O2")
#pragma GCC target("avx,avx2,fma")
#include <bits/stdc++.h>
#define FOR(i, a, b) for (int i = (a); i <= (b); i++)
#define FOD(i, a, b) for (int i = (a); i >= (b); i--)
#define REP(i, n) for (int i = 0; i < (n); i++)
#define ALL(x) (x).begin(), (x).end()
#define TIME  (1.0 * clock() / CLOCKS_PER_SEC)
#define file(name)  if (fopen(name".inp", "r")) { freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout); }
using namespace std;

const int MAXN = 3e5 + 5;
const long long INF = 1e18 + 7;

int N, K, a[MAXN];

struct SUB1{
    vector <vector <vector <long long>>> dp;
    void solve(void) {
        dp.assign(N + 2, vector <vector <long long>> (K + 2, vector <long long> (3, -INF)));
        dp[0][0][0] = 0;
        FOR(i, 0, N - 1) FOR(j, 0, K) if (dp[i][j][0] != -INF || dp[i][j][1] != INF) {
            dp[i + 1][j][0] = max(dp[i][j][0], dp[i][j][1]);
            dp[i + 1][j][1] = max(dp[i + 1][j][1], dp[i][j][1] + a[i + 1]);
            dp[i + 1][j + 1][1] = max(dp[i + 1][j + 1][1], dp[i][j][0] + a[i + 1]);
        }   
        long long ans = 0;
        FOR(i, N, N) FOR(j, 0, K) REP(c, 2) ans = max(ans, dp[i][j][c]);
        cout << ans; exit(0);
    }
} sub1;

struct SUB2{
    #define ii pair <int, int>
    #define fi first
    #define se second
    long long sum[MAXN];
    int M = 0, root[MAXN];
    ii b[MAXN];
    void solve(void) {
        FOR(i, 1, N) sum[i] = sum[i - 1] + a[i];

        FOR(i, 1, N) {
            if (a[i] < 0) continue;
            int l = i;
            while (l <= N && a[l] >= 0) l++;
            b[++M] = {i, l - 1};
            i = l - 1;
        }
        if (M <= K) {
            long long ans = 0;
            FOR(i, 1, M) ans += sum[b[i].se] - sum[b[i].fi - 1];
            cout << ans; exit(0);
        }
        long long ans = sum[N];
        FOR(i, 1, M) ans = max(ans, sum[b[i].se] - sum[b[i].fi - 1]);
        cout << ans;
    }
} sub2;

void solve(void) {
    cin >> N >> K;
    FOR(i, 1, N) cin >> a[i];
    if (1ll * N * K <= 1e7) sub1.solve();
    sub2.solve();
}

signed main(void) {
    ios_base::sync_with_stdio(false); cin.tie(nullptr); cout.tie(nullptr);
    //file("TASK");
    //int T; cin >> T; while (T--) 
    solve();
    cerr << "Time elapsed: " << TIME << " s.\n";
    return (0 ^ 0);
}
/*
6 2 
1 2 3 -10 5 6
*/

• Subtask 1: 4 / 4
• Subtask 2: 8 / 8
• Subtask 3: 18 / 18
• Subtask 4: 10 / 10
• Subtask 5: 11 / 11
• Subtask 6: 20 / 20
• Subtask 7: 0 / 29