Submission #524487

#	Time	Username	Problem	Language	Result	Execution time	Memory
524487		cqtshadow	Stove (JOI18_stove)	C++14	100 / 100	161 ms	196420 KiB

stove

#include <bits/stdc++.h>
#define MASK(x) (1LL << x)
#define GETBIT(mask, x) ((mask >> (x))&1)
#define ONBIT(mask, x) (mask | (1LL << (x)))
#define Each(type, i, a, b) for(type i = (a) ; i <= (b) ; ++i)
#define REach(type, i, a, b) for(type i = (a) ; i >= (b) ; --i)
using namespace std;

typedef long long ll;

const int N = 1e5 + 7;
const int MOD = 1e9 + 7;
const int INF = 1e9;
const double eps = 1e-9;
const ll oo = 4e18;

template<class X> bool maximize(X &x, X y) {return (x + eps < y ? x = y, true : false);}
template<class X> bool minimize(X &x, X y) {return (x > y + eps ? x = y, true : false);}

void add(int &x, int y) {x += y; if(x >= MOD) x -= MOD;}
void sub(int &x, int y) {x -= y; if(x < 0) x += MOD;}
int radd(int x, int y) {add(x, y); return x;}
int rsub(int x, int y) {sub(x, y); return x;}

string to2(int val) {bitset<10> temp(val); return temp.to_string();}

int n, k;
int t[N];

namespace SUB1 {
    int f[21][21];

    int dp(int pos, int cnt) {
        if(pos > n) return 0;
        if(cnt >= k) return INF;

        int &res = f[pos][cnt];
        if(res != -1) return res;

        res = INF;
        Each(int, i, pos, n)
            minimize(res, dp(i + 1, cnt + 1) + t[i] + 1 - t[pos]);

        return res;
    }

    void solve() {
        memset(f, -1, sizeof f);
        cout << dp(1, 0);
        exit(0);
    }
}

namespace SUB2 {
    ll f[5001][5001];

    ll dp(int pos, int cnt) {
        if(pos > n) return 0;

        ll &res = f[pos][cnt];
        if(res != -1) return res;

        res = dp(pos + 1, cnt) + t[pos] - t[pos - 1];

        if(cnt + 1 <= k)
            minimize(res, dp(pos + 1, cnt + 1) + 1);

        return res;
    }

    void solve() {
        memset(f, -1, sizeof f);
        cout << dp(2, 1) + 1;
        exit(0);
    }
}

namespace SUB3 {
    int a[N];

    void solve() {
        Each(int, i, 1, n - 1)
            a[i] = t[i + 1] - t[i];
        ll ans = t[n] - t[1] + k;
        sort(a + 1, a + n, greater<int>());
        Each(int, i, 1, k - 1)
            ans -= a[i];
        cout << ans;
    }
}

int main() {
//    #ifndef ONLINE_JUDGE
//        freopen("JOI18_stove.inp", "r", stdin);
//        freopen("JOI18_stove.out", "w", stdout);
//    #endif
    ios::sync_with_stdio(false);cin.tie(nullptr);

    cin >> n >> k;
    Each(int, i, 1, n) cin >> t[i];

    if(n <= 20) SUB1::solve();
    if(n <= 5000) SUB2::solve();
    SUB3::solve();
}

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