제출 #998484

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
998484		underwaterkillerwhale	Bigger segments (IZhO19_segments)	C++17	13 / 100	3 ms	10752 KiB

segments

#include <bits/stdc++.h>
#define se              second
#define fs              first
#define mp              make_pair
#define pb              push_back
#define ll              long long
#define ii              pair<ll,ll>
#define ld              long double
#define SZ(v)           (int)v.size()
#define ALL(v)          v.begin(), v.end()
#define bit(msk, i)     ((msk >> i) & 1)
#define iter(id, v)     for(auto id : v)
#define rep(i,m,n)      for(int i=(m); i<=(n); i++)
#define reb(i,m,n)      for(int i=(m); i>=(n); i--)

using namespace std;

mt19937_64 rd(chrono :: steady_clock :: now().time_since_epoch().count());
ll Rand(ll l, ll r) { return uniform_int_distribution<ll> (l, r)(rd); }

const int N  = 5e5 + 7;
const int Mod = 998244353;
const int szBL = 916;
const ll INF = 1e18;
const int BASE = 137;

int n;
ll a[N];
ll dp[N][2], pre[N];

struct fenwick_tree {
    int Range;
    ll fen[N];
    void init (int n) {
        Range = n;
        rep (i, 1, n) fen[i] = -1;
    }
    void update (int pos, ll val) {
        for (; pos <= Range; pos += pos & -pos) fen[pos] = max(fen[pos], val);
    }
    ll get (int pos) {
        ll res = -1;
        for (; pos > 0; pos -= pos & -pos) res = max(res, fen[pos]);
        return res;
    }
}BIT;

void solution () {
    cin >> n;
    rep (i, 1, n) cin >> a[i];
    rep (i, 1, n) pre[i] = pre[i - 1] + a[i];

    memset(dp, 0x3f, sizeof dp);
    dp[0][0] = 0;
    int res = 0;
    rep (k, 1, 60) {
        rep (i, 0, n) dp[i][k & 1] = INF;
        static vector<ll> vec; vec.clear();
        rep (i, 0, n) vec.push_back(dp[i][k&1^1] + pre[i]);
        sort (ALL(vec));
        ll nval;
        vec.resize (nval = unique(ALL(vec)) - vec.begin());
        BIT.init(nval);
        rep (i, 0, n) {
            int posprei = upper_bound(ALL(vec), pre[i]) - vec.begin();
            if (BIT.get(posprei) != -1) {
                dp[i][k & 1] = pre[i] - BIT.get(posprei);
            }
            int pos = lower_bound(ALL(vec), dp[i][k&1^1] + pre[i]) - vec.begin() + 1;
            BIT.update (pos, pre[i]);
        }
        rep (i, 0, n) {
            if (dp[i][k & 1] < INF) res = k;
        }
    }
    cout << res <<"\n";
}
#define file(name) freopen(name".inp", "r", stdin); freopen(name".out", "w", stdout);
int main () {
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
//    file ("c");
    int num_Test = 1;
//    cin >> num_Test;
    while (num_Test--)
        solution();
}
/*
5 10
1 2
3 1
4 2
5 3
1 4
2 3
3 5
4 5
3 4
1 4

*/

컴파일 시 표준 에러 (stderr) 메시지

segments.cpp: In function 'void solution()':
segments.cpp:59:44: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
   59 |         rep (i, 0, n) vec.push_back(dp[i][k&1^1] + pre[i]);
      |                                           ~^~
segments.cpp:69:52: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
   69 |             int pos = lower_bound(ALL(vec), dp[i][k&1^1] + pre[i]) - vec.begin() + 1;
      |                                                   ~^~

• Subtask 1: 13 / 13
• Subtask 2: 0 / 14
• Subtask 3: 0 / 10
• Subtask 4: 0 / 36
• Subtask 5: 0 / 27