Submission #959770

#	Time	Username	Problem	Language	Result	Execution time	Memory
959770		Yang8on	Semiexpress (JOI17_semiexpress)	C++14	48 / 100	2 ms	4956 KiB

semiexpress

#include <bits/stdc++.h>
#define Y8o "Semiexpress"
#define maxn 3005
#define ll long long
#define pii pair<int, int>
#define gb(i, j) ((i >> j) & 1)

using namespace std;

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll GetRandom(ll l, ll r)
{
    return uniform_int_distribution<ll> (l, r) (rng);
}
void iof()
{
    if(fopen(Y8o".inp", "r"))
    {
        freopen(Y8o".inp", "r", stdin);
//        freopen(Y8o".out", "w", stdout);
    }
    ios_base::sync_with_stdio(0);
    cin.tie(NULL), cout.tie(NULL);
}
void ctime()
{
    cerr << "\n" << "\nTime elapsed: " << 1000 * clock() / CLOCKS_PER_SEC << "ms\n";
}


int n, m, k;
ll A, B, C, T;
ll a[maxn];

ll sum[maxn][maxn]; /// sum[i][j] : số lượng nhiều nhất khi xét nhóm i, đặt j vt
ll dp[maxn][maxn]; /// dp[i][j] : số lượng nhiều nhất khi xét đến nhóm i, đặt j vt
void prepare()
{
    for(int i = 1, cnt = 0; i <= m; i ++, cnt = 0)
    {
        ll val = (a[i] - 1) * B;
        if(val > T) break;

        ll val2 = val, pos = a[i + 1] - 1;

        int l = a[i] + 1, r = a[i + 1] - 1, lim = a[i];
//        while(1)
//        {
//            while(l <= r)
//            {
//                int mid = (l + r) >> 1;
//                if(val2 + A * (mid - lim) > T) r = mid - 1;
//                else l = mid + 1;
//            }
//
//            if(l > pos) break;
//
//            val2 = val + (l - a[i]) * C;
//            if(val2 > T)
//            {
//                pos = l - 1;
//                break;
//            }
//
//            sum[i][cnt ++] = (l - 1) - a[i] + 1 - (i == 1);
//            lim = l ++, r = a[i + 1] - 1;
//
//            if(l > r) break;
//        }
//        sum[i][cnt] = pos - a[i] + 1 - (i == 1);
//        if(i == m) sum[i][cnt] = 1;
        for(int t = a[i] + 1; t <= a[i + 1] - 1; t ++)
        {
            val2 += A;
            if(val2 > T)
            {
                val2 = val + (t - a[i]) * C;
                if(val2 > T)
                {
                    pos = t - 1;
                    break;
                }

                sum[i][cnt ++] = (t - 1) - a[i] + 1 - (i == 1);
            }
        }
        sum[i][cnt] = pos - a[i] + 1 - (i == 1);
        if(i == m) sum[i][cnt] = 1;
    }
}

void sub2()
{
    prepare();

    for(int i = 1; i <= m; i ++)
    {
        for(int j = 0; j <= k; j ++)
        {
            for(int t = 0; t <= j; t ++)
            {
                dp[i][j] = max(dp[i][j], dp[i - 1][t] + sum[i][j - t]);
            }
        }
    }

    ll ans = 0;
    for(int t = 0; t <= k; t ++) ans = max(ans, dp[m][t]);
    cout << ans;
}

struct dl
{
    int val, i, cnt;
    bool operator < (const dl & other)
    const { return val < other.val; };
};  priority_queue<dl> q;

void sub()
{
    prepare();

    for(int i = 1; i <= m; i ++) q.push({ sum[i][0], i, 0 });

    int ans = 0;
    while(q.size())
    {
        int val = q.top().val, i = q.top().i, cnt = q.top().cnt;
        q.pop();

        if(k < cnt) continue;

        k -= cnt;
        ans += val;

        q.push({ sum[i][cnt + 1] - sum[i][cnt], i, cnt + 1 });
    }

    cout << ans;
}

void solve()
{
    cin >> n >> m >> k, k -= m;
    cin >> A >> B >> C >> T;
    for(int i = 1; i <= m; i ++) cin >> a[i];

//    sub();
    if(n <= 300) sub2();
//    else sub();
}


int main()
{
    iof();

    int nTest = 1;
//    cin >> nTest;

    while(nTest --)
    {
        solve();
    }

    ctime();
    return 0;
}

Compilation message (stderr)

semiexpress.cpp: In function 'void prepare()':
semiexpress.cpp:46:13: warning: unused variable 'l' [-Wunused-variable]
   46 |         int l = a[i] + 1, r = a[i + 1] - 1, lim = a[i];
      |             ^
semiexpress.cpp:46:27: warning: unused variable 'r' [-Wunused-variable]
   46 |         int l = a[i] + 1, r = a[i + 1] - 1, lim = a[i];
      |                           ^
semiexpress.cpp:46:45: warning: unused variable 'lim' [-Wunused-variable]
   46 |         int l = a[i] + 1, r = a[i + 1] - 1, lim = a[i];
      |                                             ^~~
semiexpress.cpp: In function 'void sub()':
semiexpress.cpp:123:51: warning: narrowing conversion of 'sum[i][0]' from 'long long int' to 'int' [-Wnarrowing]
  123 |     for(int i = 1; i <= m; i ++) q.push({ sum[i][0], i, 0 });
      |                                           ~~~~~~~~^
semiexpress.cpp:136:34: warning: narrowing conversion of '(sum[i][(cnt + 1)] - sum[i][cnt])' from 'long long int' to 'int' [-Wnarrowing]
  136 |         q.push({ sum[i][cnt + 1] - sum[i][cnt], i, cnt + 1 });
      |                  ~~~~~~~~~~~~~~~~^~~~~~~~~~~~~
semiexpress.cpp: In function 'void iof()':
semiexpress.cpp:19:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   19 |         freopen(Y8o".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 18 / 18
• Subtask 2: 30 / 30
• Subtask 3: 0 / 52