제출 #938122

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
938122		sysia	Bigger segments (IZhO19_segments)	C++17	100 / 100	154 ms	29584 KiB

segments

//Sylwia Sapkowska
#include <bits/stdc++.h>
#pragma GCC optimize("O3", "unroll-loops")
using namespace std;

void __print(int x) {cerr << x;}
void __print(long long x) {cerr << x;}
void __print(long double x) {cerr << x;}
void __print(char x) {cerr << "'" << x << "'";}
void __print(const char *x) {cerr << '"' << x << '"';}
void __print(const string &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 &i: x) cerr << (f++ ? ", " : ""), __print(i); 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 LOCAL
#define debug(x...) cerr << "[" << #x << "] = ["; _print(x)
#else
#define debug(x...)
#endif

#define int long long
typedef pair<int, int> T;
const int oo = 1e18, oo2 = 1e9+7, K = 50; 
const int mod = 998244353;

void ckmax(T &a, T b){
    if (a.first < b.first || (a.first == b.first && a.second > b.second)) a = b;
}

struct Tree{
    vector<T>tab;
    int size = 1;

    Tree(int n){
        while (size < n) size*=2;
        tab.assign(2*size, {-oo, oo});
    }

    T query(int x){
        T ans = {-oo, oo};
        x += size;
        while (x){
            ckmax(ans, tab[x]);
            x/=2;
        }
        return ans;
    }

    void update(int l, int r, T val){
        for (l += size-1, r += size+1; r-l>1; l/=2, r/=2){
            if (!(l&1)) ckmax(tab[l+1], val);
            if (r&1) ckmax(tab[r-1], val);
        }
    }
};

void solve(){
    int n; cin >> n;
    vector<int>a(n+1), pref(n+1);
    for (int i = 1; i<=n; i++){
        cin >> a[i];
        pref[i] = pref[i-1] + a[i];
    }
    Tree t(n+2);
    t.update(0, 0, {0, 0});
    // vector<T>dp(n+1, {-oo, oo});
    // dp[0] = {0, 0};
    for (int i = 0; i<n; i++){
        auto [mx, sum] = t.query(i);
        sum += pref[i];
        // auto [mx, sum] = dp[i];
        int p = max(i+1, (int)(lower_bound(pref.begin(), pref.end(), sum + pref[i])-pref.begin())); //[i+1, p]
        debug(i, mx, sum, p);
        if (p <= n) t.update(p, n, T{mx+1, -pref[i]});
        // for (int j = p; j <= n; j++){
            // ckmax(dp[j], {mx+1, pref[j]-pref[i]});
        // }
    }
    int ans = 0;
    for (int i = 1; i<=n; i++) ans = max(ans, t.query(i).first);
    cout << ans << "\n";
    // cout << dp[n].first << "\n";
}

int32_t main(){
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);

    int t = 1;
    //cin >> t;
    while (t--) solve();

    return 0;
}

• Subtask 1: 13 / 13
• Subtask 2: 14 / 14
• Subtask 3: 10 / 10
• Subtask 4: 36 / 36
• Subtask 5: 27 / 27