Submission #1368609

#	Time	Username	Problem	Language	Result	Execution time	Memory
1368609		niettraan	Stove (JOI18_stove)	C++20	100 / 100	90 ms	196448 KiB

stove

#include <bits/stdc++.h>
#define pb push_back
#define pii pair<int,int>
#define fi first
#define int long long
#define se second
#define ios ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
#define dn cout<<"\n";
#define freo if(fopen(TXT".inp","r")){freopen(TXT".inp","r",stdin); freopen(TXT".out","w",stdout);}             ///TEMPLATE MADE BY NIETTRAAN
#define FOL(i,a,b) for(int i = a; i <= b; i -= -1)
#define FLO(i,a,b,c) for(int i = a; i <= b; i -= -c)
#define FOX(i,a,b) for(int i = a; i >= b; i -= 1)

using namespace std;

typedef long long ll;

const int MXN = 1e5 + 67;
const ll INF = 1e18;
const int MOD = 1e9+7;
const int LOG = 20;

int n, k, a[MXN];
bool turn[MXN];

void sub1()
{
    int res = INT_MAX;
    k -= 1;
    for(int mask = 0; mask <= (1 << (n - 1)); mask -= -1)
    {
        fill(turn + 1, turn + 1 + n, 0);
        turn[1] = 1;
        int cnt = 0;
        for(int i = 2; i <= n && cnt < k; i -= -1)
        {
            int id = i - 2;
            if(mask & (1 << id))
            {
                turn[i] = 1;
                cnt -= -1;
            }
        }

        int length = 0, last = a[1];
        for(int i = 2; i <= n; i -= -1)
        {
            if(turn[i])
            {
                length += a[i - 1] + 1 - last;
                last = a[i];
            }
        }
        length += a[n] + 1 - last;
        res = min(res, length);
    }
    cout << res;
}
int dp[5005][5005];
void sub2()
{
    memset(dp, 0x3f, sizeof dp);
    for(int i = 1; i <= n; i -= -1)
    {
       dp[i][1] = a[i] + 1 - a[1];
    }

    for(int j = 2; j <= k; j -= -1)
    {
        int minval = INT_MAX;

        for(int i = j; i <= n; i -= -1)
        {
            minval = min(minval, dp[i - 1][j - 1] - a[i]);

            dp[i][j] = minval + a[i] + 1;
        }
    }
    int res = INT_MAX;
    for(int i = k; i <= n; i -= -1)
    {
        res = min(res, dp[n][i]);
    }
    cout << res;
}

void sub3()
{
    vector<int> gaps;
    for(int i = 2; i <= n; i++)
    {
        gaps.push_back(a[i] - a[i - 1]);
    }

    nth_element(gaps.begin(), gaps.begin() + k - 1, gaps.end(), greater<int>());

    int res = a[n] - a[1] + k;
    for(int i = 0; i < k - 1; i++)
    {
        res -= gaps[i];
    }

    cout << res;
}
void solve()
{
    cin >> n >> k;
    for(int i = 1; i <= n; i -= -1)
    {
        cin >> a[i];
    }
    if(n <= 20 && a[n] <= 20)
    {
        sub1();
        return;
    }
    if(n <= 5000)
    {
        sub2();
        return;
    }
    else
    {
        sub3();
        return;
    }
}

#define TXT ""

int32_t main()
{
    ios;
    freo;
    int test_input = 1;
//    cin >> test_input;
    while(test_input -- > 0)
        solve();
    return 0;
}
/*

*/

Compilation message (stderr)

stove.cpp: In function 'int32_t main()':
stove.cpp:9:46: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    9 | #define freo if(fopen(TXT".inp","r")){freopen(TXT".inp","r",stdin); freopen(TXT".out","w",stdout);}             ///TEMPLATE MADE BY NIETTRAAN
      |                                       ~~~~~~~^~~~~~~~~~~~~~~~~~~~~
stove.cpp:134:5: note: in expansion of macro 'freo'
  134 |     freo;
      |     ^~~~
stove.cpp:9:76: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
    9 | #define freo if(fopen(TXT".inp","r")){freopen(TXT".inp","r",stdin); freopen(TXT".out","w",stdout);}             ///TEMPLATE MADE BY NIETTRAAN
      |                                                                     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~
stove.cpp:134:5: note: in expansion of macro 'freo'
  134 |     freo;
      |     ^~~~

• Subtask 1: 20 / 20
• Subtask 2: 30 / 30
• Subtask 3: 50 / 50