Submission #1121007

#	Time	Username	Problem	Language	Result	Execution time	Memory
1121007		steveonalex	Sjeckanje (COCI21_sjeckanje)	C++17	110 / 110	549 ms	55372 KiB

Main

#include <bits/stdc++.h>

using namespace std;

typedef long long ll;
typedef unsigned long long ull;

#define MASK(i) (1LL << (i))
#define GETBIT(mask, i) (((mask) >> (i)) & 1)
#define ALL(v) (v).begin(), (v).end()

ll max(ll a, ll b){return (a > b) ? a : b;}
ll min(ll a, ll b){return (a < b) ? a : b;}

ll gcd(ll a, ll b){return __gcd(a, b);}
ll LASTBIT(ll mask){return (mask) & (-mask);}
int pop_cnt(ll mask){return __builtin_popcountll(mask);}
int ctz(ll mask){return __builtin_ctzll(mask);}
int logOf(ll mask){return __lg(mask);}

mt19937_64 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
ll rngesus(ll l, ll r){return l + (ull) rng() % (r - l + 1);}

template <class T1, class T2>
    bool maximize(T1 &a, T2 b){
        if (a < b) {a = b; return true;}
        return false;
    }

template <class T1, class T2>
    bool minimize(T1 &a, T2 b){
        if (a > b) {a = b; return true;}
        return false;
    }

template <class T>
    void printArr(T& container, string separator = " ", string finish = "\n"){
        for(auto item: container) cout << item << separator;
        cout << finish;
    }


template <class T>
    void remove_dup(vector<T> &a){
        sort(ALL(a));
        a.resize(unique(ALL(a)) - a.begin());
    }

const ll INF = 1e18 + 69;

int normalise(ll x){
    if (x == 0) return 0;
    if (x > 0) return 1;
    return -1;
}

struct SegmentTree{
    struct Node{
        ll f[2][2];
        ll val_pref, val_suff;
        int len;
        Node(){
            memset(f, 0, sizeof f);
            val_pref = val_suff = -INF;
        }

        void set_val(ll x){
            f[0][0] = abs(x);
            val_pref = val_suff = x;
        }

        void add_val(ll x){
            val_pref += x;
            val_suff += x;
            f[0][0] = abs(val_pref);
        }
    };

    int n;
    vector<Node> a;

    SegmentTree(int _n){
        n = _n;
        a.resize(n * 4 + 2);
    }

    Node combine(Node a, Node b){
        Node c;
        c.len = a.len + b.len;
        c.val_pref = a.val_pref;
        c.val_suff = b.val_suff;

        for(int x = 0; x < min(2, c.len); ++x) for(int y = 0; y < min(2, c.len); ++y){
            if (normalise(a.val_suff) * normalise(b.val_pref) != -1){
                maximize(c.f[x][y], a.f[x][0] + b.f[0][y]);
            }
            else{
                for(int i = 0; i <= 1; ++i) {
                    int j = 1 - i;
                    maximize(c.f[x][y], a.f[x][i] + b.f[j][y]);
                }
            }
        }

        for(int i = 1; i >= 1; --i) for(int j = 1; j >= 0; --j){
            maximize(c.f[i-1][j], c.f[i][j]);
        }
        return c;
    }

    void build_tree(int l, int r, int id, vector<ll> &b){
        if (l == r){
            a[id].set_val(b[l]);
            a[id].len = 1;
            return;
        }
        int mid = (l + r) >> 1;
        build_tree(l, mid, id * 2, b);
        build_tree(mid + 1, r, id * 2 + 1, b);
        a[id] = combine(a[id * 2], a[id * 2 + 1]);
    }

    void update(int i, ll x, int l, int r, int id){
        if (l == r){
            a[id].add_val(x);
            return;
        }
        int mid = (l + r) >> 1;
        if (i <= mid) update(i, x, l, mid, id * 2);
        else update(i, x, mid + 1, r, id * 2 + 1);
        // cout << "Merge: " << l << " " << r << "\n";
        a[id] = combine(a[id * 2], a[id * 2 + 1]);
    }

    void update(int i, ll x){
        if (x == 0) return;
        // cout << "I am ICPC\n";
        update(i, x, 1, n, 1);
    }

    ll get(){
        return a[1].f[0][0];
    }
};

void solve(){
    int n, q; cin >> n >> q;
    vector<ll> a(n+2);
    for(int i = 1; i<=n; ++i) cin >> a[i];
    for(int i = n; i >= 1; --i) a[i] -= a[i-1];
    a[1] = 0;

    SegmentTree st(n+1);
    st.build_tree(1, n+1, 1, a);

    while(q--){
        int l, r, x; cin >> l >> r >> x;
        if (l > 1) st.update(l, x);
        if (r + 1 <= n) st.update(r + 1, -x);

        cout << st.get() << "\n";
    }
}

int main(void){
    ios::sync_with_stdio(0); cin.tie(0); cout.tie(0);

    clock_t start = clock();
    
    solve();

    cerr << "Time elapsed: " << clock() - start << "ms!\n";
    return 0;
}

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