답안 #366787

# 제출 시각 아이디 문제 언어 결과 실행 시간 메모리
366787 2021-02-15T09:51:24 Z mickeyandkaka Feast (NOI19_feast) C++17
59 / 100
118 ms 16364 KB
//{{{
#include <bits/stdc++.h>
using namespace std;
using LL = long long;
using VLL = vector<LL>;
using vi = vector<int>;
using pii = pair<int, int>;
#define sz(x) (int)((x).size())
#define all(x) (x).begin(), (x).end()
#define clr(a, b) memset(a, b, sizeof(a))
#ifdef LOCAL
#include "prettyprint.hpp"
// clang-format off
void _print() { cerr << "]\033[0m\n"; }
template <typename T> void __print(T x) { cerr << x; }
template <typename T, typename... V> void _print(T t, V... v) { __print(t); if (sizeof...(v)) cerr << ", "; _print(v...); }
#define debug(x...) cerr << "\033[1;34m[" << #x << "] = \033[1;32m["; _print(x)
#define debug_arr(x...) cerr << "\033[1;34m[" << #x << "] = \033[1;32m" << (x) << "\033[0m\n"
#else
#define debug(x...)
#define debug_arr(x...)
#endif
// clang-format on
//}}}

const int N = 3e5 + 10;
// const int N = 10;
int n, k;
int a[N];
LL s[N];

LL dp[N];
LL cnt[N];

LL minf[N];
LL minf_p[N];

int check(LL c)
{
    dp[0] = 0, cnt[0] = 0;
    minf[0] = dp[0] - s[0];
    minf_p[0] = 0;

    for (int i = 1; i <= n; i++)
    {
        dp[i] = dp[i - 1];
        cnt[i] = cnt[i - 1];

        if (minf[i - 1] + s[i] - c > dp[i])
        {
            dp[i] = minf[i - 1] + s[i] - c;
            // debug(i, dp[i]);

            cnt[i] = cnt[minf_p[i - 1]] + 1;
        }

        else if (minf[i - 1] + s[i] - c == dp[i])
        {
            if (cnt[i] < cnt[minf_p[i - 1]] + 1)
            {
                dp[i] = minf[i - 1] + s[i] - c;
                cnt[i] = cnt[minf_p[i - 1]] + 1;
            }
        }

        minf[i] = minf[i - 1];
        minf_p[i] = minf_p[i - 1];

        if (dp[i] - s[i] > minf[i])
        {
            minf[i] = dp[i] - s[i];
            minf_p[i] = i;
        }
    }
    // if (cnt[n] == 0) return k + 1;
    return cnt[n];
}

// const int NN = 1e3 + 10;
// LL dp2[NN][NN];

int main()
{
#ifdef LOCAL
    freopen("in", "r", stdin);
    // freopen("out", "w", stdout);
#endif

    ios::sync_with_stdio(false);
    cin.tie(0);

    while (cin >> n >> k)
    {
        for (int i = 1; i <= n; ++i) cin >> a[i];
        s[0] = 0;
        for (int i = 1; i <= n; ++i) s[i] = s[i - 1] + a[i];

        // clr(dp2, 0x80);

        // dp2[0][0] = 0;
        // for (int i = 1; i <= n; i++)
        //{
        // dp2[i][0] = 0;
        // for (int j = 1; j <= i; j++)
        //{
        // dp2[i][j] = dp2[i - 1][j];
        // for (int p = 0; p < i; p++)
        //{
        // dp2[i][j] = max(dp2[i][j], dp2[p][j - 1] + s[i] - s[p]);
        //}
        //}
        //}

        // for (int p = 1; p <= n; ++p)
        //{
        // debug(p, dp2[n][p]);
        //}

        // for (int kk = max(1, k - 15); kk <= min(1000, k + 15); kk++)
        //{
        // debug(kk, dp2[n][kk], dp2[n][kk] - dp2[n][kk - 1]);
        //// cout << kk << "," << dp2[n][kk] << endl;
        //}

        // for (int i = -10; i <= 1; i++)
        //{
        // int v = check(i);
        // debug(i, v, cnt[n], dp[n]);
        //}

        // mid越大 段数越小
        // 段数不超过k
        // mid尽可能小

        LL lo = -1e15, hi = 1e15;
        while (lo + 1 < hi)
        {
            LL mid = lo + (hi - lo) / 2;

            if (check(mid) >= k)
            {
                lo = mid;
            }
            else
            {
                hi = mid;
            }
        }
        LL c = lo;
        if (check(hi) >= k) c = hi;
        debug(lo, hi, c);

        int v = check(c);

        debug(c, v);
        debug(cnt[n], k, dp[n]);

        LL ans = dp[n] + c * k;

        LL ans2 = ans;
        v = check(0);
        if (cnt[n] <= k && dp[n] > ans) ans2 = dp[n];
        ans = max(ans, ans2);

        cout << ans << endl;
    }

    return 0;
}

Compilation message

feast.cpp: In function 'int main()':
feast.cpp:153:13: warning: variable 'v' set but not used [-Wunused-but-set-variable]
  153 |         int v = check(c);
      |             ^
# 결과 실행 시간 메모리 Grader output
1 Incorrect 96 ms 15724 KB Output isn't correct
2 Halted 0 ms 0 KB -
# 결과 실행 시간 메모리 Grader output
1 Correct 80 ms 14060 KB Output is correct
2 Correct 79 ms 14316 KB Output is correct
3 Correct 87 ms 14188 KB Output is correct
4 Incorrect 80 ms 14188 KB Output isn't correct
5 Halted 0 ms 0 KB -
# 결과 실행 시간 메모리 Grader output
1 Correct 113 ms 16108 KB Output is correct
2 Correct 114 ms 15980 KB Output is correct
3 Correct 114 ms 16108 KB Output is correct
4 Correct 113 ms 15980 KB Output is correct
5 Correct 111 ms 16108 KB Output is correct
6 Correct 116 ms 16236 KB Output is correct
7 Correct 114 ms 16364 KB Output is correct
8 Correct 112 ms 16108 KB Output is correct
9 Correct 118 ms 16364 KB Output is correct
10 Correct 114 ms 16236 KB Output is correct
# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 364 KB Output is correct
2 Correct 1 ms 400 KB Output is correct
3 Correct 1 ms 364 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 1 ms 364 KB Output is correct
6 Correct 1 ms 364 KB Output is correct
7 Correct 1 ms 364 KB Output is correct
8 Correct 1 ms 364 KB Output is correct
9 Correct 1 ms 364 KB Output is correct
10 Correct 1 ms 364 KB Output is correct
# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 364 KB Output is correct
2 Correct 1 ms 400 KB Output is correct
3 Correct 1 ms 364 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 1 ms 364 KB Output is correct
6 Correct 1 ms 364 KB Output is correct
7 Correct 1 ms 364 KB Output is correct
8 Correct 1 ms 364 KB Output is correct
9 Correct 1 ms 364 KB Output is correct
10 Correct 1 ms 364 KB Output is correct
11 Correct 1 ms 364 KB Output is correct
12 Correct 1 ms 364 KB Output is correct
13 Correct 1 ms 364 KB Output is correct
14 Correct 1 ms 364 KB Output is correct
15 Correct 1 ms 364 KB Output is correct
16 Correct 1 ms 364 KB Output is correct
17 Correct 1 ms 364 KB Output is correct
18 Correct 1 ms 364 KB Output is correct
19 Correct 1 ms 364 KB Output is correct
20 Correct 1 ms 364 KB Output is correct
# 결과 실행 시간 메모리 Grader output
1 Correct 1 ms 364 KB Output is correct
2 Correct 1 ms 400 KB Output is correct
3 Correct 1 ms 364 KB Output is correct
4 Correct 1 ms 364 KB Output is correct
5 Correct 1 ms 364 KB Output is correct
6 Correct 1 ms 364 KB Output is correct
7 Correct 1 ms 364 KB Output is correct
8 Correct 1 ms 364 KB Output is correct
9 Correct 1 ms 364 KB Output is correct
10 Correct 1 ms 364 KB Output is correct
11 Correct 1 ms 364 KB Output is correct
12 Correct 1 ms 364 KB Output is correct
13 Correct 1 ms 364 KB Output is correct
14 Correct 1 ms 364 KB Output is correct
15 Correct 1 ms 364 KB Output is correct
16 Correct 1 ms 364 KB Output is correct
17 Correct 1 ms 364 KB Output is correct
18 Correct 1 ms 364 KB Output is correct
19 Correct 1 ms 364 KB Output is correct
20 Correct 1 ms 364 KB Output is correct
21 Correct 2 ms 492 KB Output is correct
22 Correct 2 ms 492 KB Output is correct
23 Correct 2 ms 492 KB Output is correct
24 Correct 1 ms 492 KB Output is correct
25 Correct 2 ms 492 KB Output is correct
26 Correct 1 ms 492 KB Output is correct
27 Correct 2 ms 492 KB Output is correct
28 Correct 1 ms 492 KB Output is correct
29 Correct 1 ms 492 KB Output is correct
30 Correct 1 ms 492 KB Output is correct
# 결과 실행 시간 메모리 Grader output
1 Incorrect 96 ms 15724 KB Output isn't correct
2 Halted 0 ms 0 KB -