Submission #1268216

#	Time	Username	Problem	Language	Result	Execution time	Memory
1268216		pqhxapple	Feast (NOI19_feast)	C++20	100 / 100	89 ms	12104 KiB

feast

#include <bits/stdc++.h>

using namespace std;

#define FOR(i,a,b)      for (int i = (a), _b = (b); i <= (_b); ++i)
#define FORD(i,a,b)     for (int i = (a), _b = (b); i >= (_b); --i)
#define getBit(mask,i)  (((mask) >> (i)) & (1LL))
#define allof(x)        begin(x), end(x)
#define el              cout << '\n';

//--Compare------------------------------------------------------------------------------------
template<class X, class Y> 
    inline bool maximize(X &x, const Y &y){ return (x < y) ? x = y, 1 : 0; }

template<class X, class Y> 
    inline bool minimize(X &x, const Y &y){ return (x > y) ? x = y, 1 : 0; }

//--Process------------------------------------------------------------------------------------

#define int             long long
#define fi              first
#define se              second
typedef pair <int, int> ii;

constexpr int MAXN = 3e5 + 10;
int n, k;
int a[MAXN];
ii dp[MAXN][2];

signed main(void)
{
    cin.tie(nullptr)->sync_with_stdio(false);
    cin.exceptions(cin.failbit);
    
    cin >> n >> k;
    FOR(i, 1, n) cin >> a[i];

    
    function <ii(int)> calc = [&](int lmb)
    {
        dp[1][0] = {0, 0};
        dp[1][1] = {a[1] - lmb, 1};

        FOR(i, 2, n)
        {
            dp[i][0] = max(dp[i - 1][0], dp[i - 1][1]);

            ii val1 = make_pair(dp[i - 1][0].fi + a[i] - lmb, dp[i - 1][0].se + 1);
            ii val2 = make_pair(dp[i - 1][1].fi + a[i], dp[i - 1][1].se);
            dp[i][1] = max(val1, val2);
        }
        return max(dp[n][0], dp[n][1]);
    };

    int low = 0, high = 1e18;
    while (low < high)
    {
        int mid = (low + high + 1) / 2;
        calc(mid).se >= k ? low = mid : high = mid - 1;
    }

    cout << calc(low).fi + low * k << '\n';

    cerr << (1.0 * clock() / CLOCKS_PER_SEC);
    return 0;
}

• 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: 29 / 29