Submission #873936

#	Time	Username	Problem	Language	Result	Execution time	Memory
873936		kh0i	Sjeckanje (COCI21_sjeckanje)	C++17	0 / 110	1 ms	348 KiB

Main

#include "bits/stdc++.h"
using namespace std;

#ifdef LOCAL
#include "debug.h"
#else
#define debug(...)
#endif

using ll = long long;
using pii = pair<int, int>;

#define F first
#define S second
#define sz(x) (int)((x).size())
#define all(x) (x).begin(), (x).end()

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());
ll get_rand(ll l, ll r) {
    assert(l <= r);
    return uniform_int_distribution<ll> (l, r)(rng);
}

#define sgn(x) ((x > 0) - (x < 0))

const ll INF = 1e18;
const int N = 2e5 + 3;

int n, m;
ll a[N];

struct ST{
    struct Node{
        ll dak[2][2];
    };

    vector<Node> st;

    void init(int _n){
        n = _n;
        st.resize(4 * n + 6);
    }

    Node combine(Node &x, Node &y, int mid){
        Node res;
        res.dak[0][0] = max({x.dak[0][1] + y.dak[0][0], x.dak[0][0] + y.dak[1][0], x.dak[0][0] + y.dak[0][0]});
        res.dak[1][0] = max({x.dak[1][1] + y.dak[1][0], x.dak[1][0] + y.dak[1][0], x.dak[1][0] + y.dak[0][0]});
        res.dak[0][1] = max({x.dak[0][1] + y.dak[0][1], x.dak[0][0] + y.dak[0][1], x.dak[0][0] + y.dak[1][1]});
        res.dak[1][1] = max({x.dak[1][1] + y.dak[0][1], x.dak[1][0] + y.dak[1][1], x.dak[1][0] + y.dak[0][1]});

        if(sgn(a[mid]) * sgn(a[mid + 1]) >= 0){
            res.dak[0][0] = max(res.dak[0][0], x.dak[0][1] + y.dak[1][0]);
            res.dak[0][1] = max(res.dak[0][1], x.dak[0][1] + y.dak[1][1]);
            res.dak[1][0] = max(res.dak[1][0], x.dak[1][1] + y.dak[1][0]);
            res.dak[1][1] = max(res.dak[1][1], x.dak[1][1] + y.dak[1][1]);
        }
        return res;
    }

    void _build(int id, int l, int r){
        if(l == r){
            st[id].dak[0][1] = st[id].dak[1][0] = -INF;
            st[id].dak[1][1] = abs(a[l]);
            st[id].dak[0][0] = 0;
            return;
        }
        int mid = (l + r) / 2;
        _build(2 * id, l, mid);
        _build(2 * id + 1, mid + 1, r);
        st[id] = combine(st[2 * id], st[2 * id + 1], mid);
    }

    void _update(int id, int l, int r, int pos){
        if(pos < l or pos > r)
            return;
        if(l == r){
            st[id].dak[0][1] = st[id].dak[1][0] = -INF;
            st[id].dak[1][1] = abs(a[l]);
            st[id].dak[0][0] = 0;
            return;
        }
        int mid = (l + r) / 2;
        if(pos <= mid)
            _update(2 * id, l, mid, pos);
        else
            _update(2 * id + 1, mid + 1, r, pos);
        st[id] = combine(st[2 * id], st[2 * id + 1], mid);
    }

    void build(){
        _build(1, 1, n);
    }

    void update(int pos){
        if(pos < 1 or pos > n)
            return;
        _update(1, 1, n, pos);
    }

    ll query(){
        return max({st[1].dak[0][0], st[1].dak[0][1], st[1].dak[1][0], st[1].dak[1][1]});
    }
} dak;

void solve(){
    cin >> n >> m;
    for(int i = 1; i <= n; ++i)
        cin >> a[i];
    for(int i = 1; i < n; ++i)
        a[i] = a[i] - a[i + 1];
    n--;
    dak.init(n);
    dak.build();

    while(m--){
        int l, r;
        ll x;
        cin >> l >> r >> x;
        a[l - 1] -= x;
        a[r] += x;
        dak.update(l - 1);
        dak.update(r);
        cout << dak.query() << '\n';
    }
}

int32_t main() {
    cin.tie(nullptr)->sync_with_stdio(0);
    #define task "troll"
    if(fopen(task".inp", "r")){
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }
    int test = 1;
//    cin >> test;
    for(int i = 1; i <= test; ++i){
//        cout << "Case #" << i << ": ";
        solve();
    }
    #ifdef LOCAL
        cerr << "\n[Time]: " << 1000.0 * clock() / CLOCKS_PER_SEC << " ms.\n";
    #endif
    return 0;
}

Compilation message (stderr)

Main.cpp: In function 'int32_t main()':
Main.cpp:131:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  131 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
Main.cpp:132:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  132 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 0 / 15
• Subtask 2: 0 / 40
• Subtask 3: 0 / 55