oj.uz

Submission #615340

# Submission time Handle Problem Language Result Execution time Memory
615340 2022-07-31T08:29:20 Z wiwiho Seesaw (JOI22_seesaw) C++14
100 / 100
 321 ms 22764 KB 
#include <bits/stdc++.h>
#include <bits/extc++.h>

#define StarBurstStream ios_base::sync_with_stdio(false); cin.tie(0); cout.tie(0);
#define iter(a) a.begin(), a.end()
#define riter(a) a.rbegin(), a.rend()
#define lsort(a) sort(iter(a))
#define gsort(a) sort(riter(a))
#define pb(a) push_back(a)
#define eb(a) emplace_back(a)
#define pf(a) push_front(a)
#define ef(a) emplace_front(a)
#define pob pop_back()
#define pof pop_front()
#define mp(a, b) make_pair(a, b)
#define F first
#define S second
#define mt make_tuple
#define gt(t, i) get<i>(t)
#define tomax(a, b) ((a) = max((a), (b)))
#define tomin(a, b) ((a) = min((a), (b)))
#define topos(a) ((a) = (((a) % MOD + MOD) % MOD))
#define uni(a) a.resize(unique(iter(a)) - a.begin())
#define printv(a, b) {bool pvaspace=false; \
for(auto pva : a){ \
    if(pvaspace) b << " "; pvaspace=true;\
    b << pva;\
}\
b << "\n";}

using namespace std;
using namespace __gnu_pbds;

typedef long long ll;
typedef unsigned long long ull;
typedef long double ld;

using pii = pair<int, int>;
using pll = pair<ll, ll>;
using pdd = pair<ld, ld>;
using tiii = tuple<int, int, int>;

const ll MOD = 1000000007;
const ll MAX = 2147483647;

template<typename A, typename B>
ostream& operator<<(ostream& o, pair<A, B> p){
    return o << '(' << p.F << ',' << p.S << ')';
}

ll ifloor(ll a, ll b){
    if(b < 0) a *= -1, b *= -1;
    if(a < 0) return (a - b + 1) / b;
    else return a / b;
}

ll iceil(ll a, ll b){
    if(b < 0) a *= -1, b *= -1;
    if(a > 0) return (a + b - 1) / b;
    else return a / b;
}

struct Comp{
    bool operator()(pll xc, pll yc){
        return (__int128)xc.F * yc.S < (__int128)yc.F * xc.S;
    }
};

void waassert(bool t){
    if(t) return;
    cout << "WA\n";
    exit(0);
}

int main(){
    StarBurstStream

    int n;
    cin >> n;

    vector<ll> a(n + 1), s(n + 1);
    for(int i = 1; i <= n; i++) cin >> a[i], s[i] = s[i - 1] + a[i];

    auto getcen = [&](int l, int r){
        return mp(s[r] - s[l - 1], r - l + 1);
    };
    auto comp = [&](pll xc, pll yc){
        return (__int128)xc.F * yc.S < (__int128)yc.F * xc.S;
    };
    auto getdis = [&](pll x, pll y){
        ld tx = (ld)x.F / x.S;
        ld ty = (ld)y.F / y.S;
        return abs(tx - ty);
    };
    
    pll mid = getcen(1, n);
    vector<pii> good;
    vector<pii> lg(n + 1), rg(n + 1);
    lg[n] = rg[n] = mp(1, n);

    for(int i = 0; i < n - 1; i++){
        {
            int l = 1, r = n - i;
            while(l < r){
                int m = (l + r) / 2;
                if(comp(getcen(m, m + i), mid)) l = m + 1;
                else r = m;
            }
            rg[i + 1] = mp(l, l + i);
        }
        {
            int l = 1, r = n - i;
            while(l < r){
                int m = (l + r + 1) / 2;
                if(comp(mid, getcen(m, m + i))) r = m - 1;
                else l = m;
            }
            good.eb(mp(l, l + i));
            lg[i + 1] = mp(l, l + i);
        }
    }
    /*printv(lg, cerr);
    printv(rg, cerr);*/

    sort(iter(good), [&](pii x, pii y){ return comp(getcen(x.F, x.S), getcen(y.F, y.S)); });
    reverse(iter(good));

    multiset<pll, Comp> st;
    for(int i = 1; i <= n; i++){
        st.insert(getcen(rg[i].F, rg[i].S));
    }

    ld ans = getdis(*st.begin(), *st.rbegin());
    /*cerr << "test ";
    printv(st, cerr);*/
    for(pll i : good){
        int len = i.S - i.F + 1;
        auto it = st.find(getcen(rg[len].F, rg[len].S));
        st.erase(it);
        st.insert(getcen(i.F, i.S));
        /*cerr << "test " << i << " : ";
        printv(st, cerr);*/
        ans = min(ans, getdis(*st.begin(), *st.rbegin()));
    }

    cout << fixed << setprecision(20) << ans << "\n";

    return 0;
}

Subtask #1
1.0 / 1.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct

Subtask #2
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct

Subtask #3
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 2 ms 468 KB Output is correct
9 Correct 2 ms 468 KB Output is correct
10 Correct 3 ms 468 KB Output is correct
11 Correct 2 ms 468 KB Output is correct

Subtask #4
33.0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 0 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 0 ms 212 KB Output is correct
5 Correct 1 ms 212 KB Output is correct
6 Correct 1 ms 212 KB Output is correct
7 Correct 0 ms 212 KB Output is correct
8 Correct 2 ms 468 KB Output is correct
9 Correct 2 ms 468 KB Output is correct
10 Correct 3 ms 468 KB Output is correct
11 Correct 2 ms 468 KB Output is correct
12 Correct 320 ms 22508 KB Output is correct
13 Correct 254 ms 22724 KB Output is correct
14 Correct 321 ms 22504 KB Output is correct
15 Correct 250 ms 22764 KB Output is correct
16 Correct 252 ms 22596 KB Output is correct