Submission #477568

#	Time	Username	Problem	Language	Result	Execution time	Memory
477568		ljuba	Sjeckanje (COCI21_sjeckanje)	C++17	110 / 110	846 ms	50752 KiB

Main

#include <bits/stdc++.h>
 
using namespace std;
 
typedef long long ll;
typedef long double ld;
 
typedef vector<int> vi;
typedef vector<ll> vll;
 
typedef vector<vi> vvi;
typedef vector<vll> vvll;
 
typedef pair<int, int> pii;
typedef pair<ll, ll> pll;
 
typedef vector<pii> vpii;
typedef vector<pll> vpll;
 
typedef vector<vpii> vvpii;
typedef vector<vpll> vvpll;
 
#define pb push_back
#define mp make_pair
#define all(x) (x).begin(), (x).end()
#define rall(x) (x).rbegin(), (x).rend()
#define sz(x) (int)(x).size()
#define fi first
#define se second
 
template<class T> bool ckmin(T &a, const T &b) {return a > b ? a = b, 1 : 0;}
template<class T> bool ckmax(T &a, const T &b) {return a < b ? a = b, 1 : 0;}
 
namespace debug {
    void __print(int x) {cerr << x;}
    void __print(long long x) {cerr << x;}
    void __print(double x) {cerr << x;}
    void __print(long double x) {cerr << x;}
    void __print(char x) {cerr << '\'' << x << '\'';}
    void __print(const string &x) {cerr << '\"' << x << '\"';}
    void __print(const char *x) {cerr << '\"' << x << '\"';}
    void __print(bool x) {cerr << (x ? "true" : "false");}
 
    template<typename T, typename V>
    void __print(const pair<T, V> &x) {cerr << '{'; __print(x.first); cerr << ','; __print(x.second); cerr << '}';}
    template<typename T>
    void __print(const T &x) {int f = 0; cerr << '{'; for(auto z : x) cerr << (f++ ? "," : ""), __print(z); cerr << "}";}
    void _print() {cerr << "]\n";}
    template <typename T, typename... V>
    void _print(T t, V... v) {__print(t); if(sizeof...(v)) cerr << ", "; _print(v...);}
 
#ifdef ljuba
#define dbg(x...) cerr << "\e[91m" << "LINE(" << __LINE__ << ") -> " << "[" << #x << "] = ["; _print(x)
#else
#define dbg(x...)
#endif
}
 
using namespace debug;
 
const char nl = '\n';
 
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
 
/*
погледај сампле тестове, пре него што имплементираш (можда имаш погрешну идеју) 
уместо да разматраш неке глупе случајеве на папиру, размишљај заправо о задатку
*/

struct node {
    ll ans[2][2];
    ll prvi, posl;
};

const int mxN = 2e5 + 12;
const ll INF = 1e18 + 12;

node merge(const node &a, const node &b) {
    bool ok1 = (a.posl > 0);
    bool ok2 = (b.prvi > 0);

    node ans;
    for(int i = 0; i < 2; ++i) {
        for(int j = 0; j < 2; ++j) {
            ans.ans[i][j] = -INF;
        }
    }
    ans.prvi = a.prvi;
    ans.posl = b.posl;

    for(int i = 0; i < 2; ++i) {
        for(int j = 0; j < 2; ++j) {
            for(int k = 0; k < 2; ++k) {
                for(int l = 0; l < 2; ++l) {
                    if(ok1^ok2) {
                        //moraju biti razliciti
                        if(j == 0 && k == 0)
                            continue;
                        ckmax(ans.ans[i][l], a.ans[i][j] + b.ans[k][l]);
                    } else {
                        ckmax(ans.ans[i][l], a.ans[i][j] + b.ans[k][l]);
                    }
                }
            }
        }
    }

    return ans;
}

class SegmentTree {
private:
    int n;
    node st[4*mxN];

    void build(const vll &v, int i, int l2, int r2) {
        if(l2 == r2) {
            st[i].prvi = v[l2];
            st[i].posl = v[l2];
            st[i].ans[0][0] = llabs(v[l2]);
            st[i].ans[0][1] = st[i].ans[1][0] = -INF;
            st[i].ans[1][1] = 0;
            return;
        }

        int m2 = (l2 + r2) / 2;
        build(v, 2*i, l2, m2);
        build(v, 2*i+1, m2+1, r2);
        st[i] = merge(st[2*i], st[2*i+1]);
    }

    void update(int l1, ll x, int i, int l2, int r2) {
        if(l2 == r2) {
            st[i].prvi += x;
            st[i].posl += x;
            st[i].ans[0][0] = llabs(st[i].prvi);
            st[i].ans[0][1] = st[i].ans[1][0] = -INF;
            st[i].ans[1][1] = 0;
            return;
        }

        int m2 = (l2 + r2) / 2;
        if(l1 <= m2) update(l1, x, 2*i, l2, m2);
        else update(l1, x, 2*i+1, m2+1, r2);
        st[i] = merge(st[2*i], st[2*i+1]);
    }

    void nz(int i, int l2, int r2) {
        if(l2 == r2) {
            int vred = st[i].prvi;
            dbg(l2, vred);
            return;
        }

        int m2 = (l2 + r2) / 2;
        nz(2*i, l2, m2);
        nz(2*i+1, m2+1, r2);
    }

public:
    SegmentTree(int _n) : n(_n) {}

    void build(const vll &v) {
        build(v, 1, 0, n-1);
    }

    void update(int l1, ll x) {
        update(l1, x, 1, 0, n-1);
    }

    ll query() {
        ll ans = -INF;
        for(int i = 0; i < 2; ++i) {
            for(int j = 0; j < 2; ++j) {
                ckmax(ans, st[1].ans[i][j]);
            }
        }
        return ans;
    }

    void nz() {
        nz(1, 0, n-1);
    }
};

void solve() {
    int n, q;
    cin >> n >> q;
    vll v(n);
    for(auto &z : v)
        cin >> z;

    if(n == 1) {
        for(int i = 0; i < q; ++i) {
            cout << 0 << nl;
        }
        return;
    }

    vll raz(n-1);
    for(int i = 1; i < n; ++i) {
        raz[i-1] = v[i] - v[i-1];
    }

    SegmentTree st(n-1);
    st.build(raz);

    //st.nz();
    //cout << st.query() << nl;

    while(q--) {
        int l, r;
        ll x;
        cin >> l >> r >> x;
        --l, --r;
        if(l-1 >= 0) {
            st.update(l-1, x);
            //dbg("levi");
        }
        if(r <= n-2) {
            st.update(r, -x);
            //dbg("desni");
        }

        //st.nz();

        cout << st.query() << nl;
    }
}
 
int main() {
    ios::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
 
    int testCases = 1;
    //cin >> testCases;
    while(testCases--)
        solve();
}

Compilation message (stderr)

Main.cpp: In member function 'void SegmentTree::nz(int, int, int)':
Main.cpp:150:17: warning: unused variable 'vred' [-Wunused-variable]
  150 |             int vred = st[i].prvi;
      |                 ^~~~

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