Submission #343680

#	Time	Username	Problem	Language	Result	Execution time	Memory
343680		spike1236	Bigger segments (IZhO19_segments)	C++14	100 / 100	950 ms	259564 KiB

segments

#include <bits/stdc++.h>
using namespace std;
#define pb push_back
#define mp make_pair
#define f first
#define s second
#define ll long long
#define ld long double
#define all(_v) _v.begin(), _v.end()
#define sz(_v) (int)_v.size()
#define pii pair <int, int>
#define pll pair <ll, ll>
#define veci vector <int>
#define vecll vector <ll>


const int dx[4] = {1, -1, 0, 0};
const int dy[4] = {0, 0, -1, 1};
const double PI = 3.1415926535897932384626433832795;
const double eps = 1e-9;
const int MOD1 = 1e9 + 7;
const int MOD2 = 998244353;

const int MAXN = 5e5 + 10;
ll pref[MAXN];
ll a[MAXN];
pll dp[MAXN];
int n;

pii t[MAXN * 40];
int ls[MAXN * 40];
int rs[MAXN * 40];
int sz = 1;

void upd(ll pos, pll val, int v = 1, ll tl = 1, ll tr = 1e15) {
    if(tl == tr) {
        t[v] = val;
        return;
    }
    ll tm = tl + tr >> 1;
    if(pos <= tm) {
        if(!ls[v]) ls[v] = ++sz;
        upd(pos, val, ls[v], tl, tm);
    } else {
        if(!rs[v]) rs[v] = ++sz;
        upd(pos, val, rs[v], tm + 1, tr);
    }
    t[v] = max(t[ls[v]], t[rs[v]]);
}

pll get(ll l, ll r, int v = 1, ll tl = 1, ll tr = 1e15) {
    if(l <= tl && tr <= r) return t[v];
    if(l > tr || r < tl) return mp(0, 0);
    ll tm = tl + tr >> 1;
    return max(get(l, r, ls[v], tl, tm), get(l, r, rs[v], tm + 1, tr));
}

void solve() {
    cin >> n;
    for(int i = 1; i <= n; ++i) cin >> a[i], pref[i] = pref[i - 1] + a[i];
    for(int i = 1; i <= n; ++i) {
        upd(pref[i - 1] * 2 - pref[dp[i - 1].s], mp(dp[i - 1].f, i - 1));
        dp[i] = get(0, pref[i]);
        dp[i].f++;
    }
    cout << dp[n].f;
}


int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    cout.tie(0);
    int T = 1;
    ///cin >> T;
    while(T--) solve(), cout << '\n';
    return 0;
}

Compilation message (stderr)

segments.cpp: In function 'void upd(long long int, std::pair<long long int, long long int>, int, long long int, long long int)':
segments.cpp:40:16: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   40 |     ll tm = tl + tr >> 1;
      |             ~~~^~~~
segments.cpp: In function 'std::pair<long long int, long long int> get(long long int, long long int, int, long long int, long long int)':
segments.cpp:54:16: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   54 |     ll tm = tl + tr >> 1;
      |             ~~~^~~~

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