Submission #1124776

#	Time	Username	Problem	Language	Result	Execution time	Memory
1124776		wibulord	Feast (NOI19_feast)	C++20	100 / 100	221 ms	13304 KiB

feast

#include <bits/stdc++.h>
#define endl '\n'
#define ll long long
#define fi first
#define se second
#define pb emplace_back
#define ii pair<ll, int>
#define MASK(i) (1LL << (i))
#define BIT(x, i) (((x) >> (i)) & 1)
#define sz(s) (int)((s).size())
#define all(a) a.begin(), a.end()
#define FOR(i, a, b) for (int i = (a), _b = (b); i <= _b; ++i)
#define F0R(i, b) for (int i = 0, _b = (b); i < _b; ++i)
#define FORd(i, a, b) for (int i = (a), _b = (b); i >= _b; --i)
#define F0Rd(i, b) for (int i = (b)-1; i >= 0; i--)
#define debug(...) " [" << #__VA_ARGS__ ": " << (__VA_ARGS__) << "] "
using namespace std;

template<typename T1,typename T2> bool ckmax(T1 &x,const T2 &y){if(x<y){x=y; return 1;} return 0;}
template<typename T1,typename T2> bool ckmin(T1 &x,const T2 &y){if(y<x){x=y; return 1;} return 0;}

const int MOD = (int)1e9 + 7;
const int mod = 998244353;
const int N = 3e5 + 10, M = 18;
const long long INF = (long long)4e18 + 11;

/*
     /\_/\
    (= ._.)
    / >?  \>$
*/

int n, k;
int A[N], L[N], R[N];
long long b[N];

int sign(int x){
    if(x == 0) return 0;
    return (x > 0 ? 1 : -1);
}

void sol(void){
    cin >> n >> k;
    FOR(i, 1, n) cin >> A[i];

    int m = 0, i = 1;
    while(A[i] <= 0) ++i;
    while(i <= n){
        ++m;
        int j = i;
        while(j <= n && sign(A[i]) * sign(A[j]) >= 0) b[m] += A[j++];
        i = j;
    }
    if(b[m] <= 0) m--;
    // FOR(i, 1, m) cout << b[i] << " \n"[i == m];

    set<ii> s;
    FOR(i, 2, m) L[i] = i-1;
    FOR(i, 1, m-1) R[i] = i+1;
    FOR(i, 1, m) s.insert(make_pair(abs(b[i]), i));
    int cnt = m/2 + 1;
    while(cnt > k){
        long long v, p; tie(v, p) = *s.begin();
        int l = L[p], r = R[p];
        s.erase(s.begin());
        if(l > 0) s.erase({abs(b[l]), l});
        if(r > 0) s.erase({abs(b[r]), r});
        if(v > 0 || (l > 0 && r > 0)) cnt--;

        b[p] += b[l] + b[r];
        b[l] = b[r] = 0;
        if(l > 0) R[L[l]] = p, L[p] = L[l];
        if(r > 0) L[R[r]] = p, R[p] = R[r];

        if(b[p] <= 0 && (l == 0 || r == 0)) b[p] = R[L[l]] = L[R[r]] = 0;
        else s.insert({abs(b[p]), p});
    }
    long long res = 0;
    FOR(i, 1, m) if(b[i] > 0) res += b[i];
    cout << res << '\n';
}

signed main(void){
    #define TASK "BANQUET"
    if(fopen(TASK".inp", "r")){
        freopen(TASK".inp", "r", stdin);
        freopen(TASK".out", "w", stdout);
    }
    ios_base::sync_with_stdio(false); cin.tie(NULL); cout.tie(NULL);
    int t = 1;
//    cin >> t;
    while(t--) sol();
    cerr << "\nTime elapsed: " << 1000 * clock() / CLOCKS_PER_SEC << " ms\n";
}

Compilation message (stderr)

feast.cpp: In function 'int main()':
feast.cpp:86:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   86 |         freopen(TASK".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
feast.cpp:87:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   87 |         freopen(TASK".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• 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