oj.uz

Submission #615333

# Submission time Handle Problem Language Result Execution time Memory
615333 2022-07-31T08:27:04 Z wiwiho Seesaw (JOI22_seesaw) C++14
67 / 100
 1238 ms 1048576 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);
    };
    
    vector<pii> tmp;
    for(int i = 1; i <= n; i++){
        for(int j = i; j <= n; j++) tmp.eb(mp(i, j));
    }
    sort(iter(tmp), [&](pii x, pii y){
        pll xc = getcen(x.F, x.S);
        pll yc = getcen(y.F, y.S);
        return comp(xc, yc);
    });

    pll mid = getcen(1, n);
    vector<pii> good;
    vector<pii> lg(n + 1), rg(n + 1);
    lg[n] = rg[n] = mp(1, n);
    waassert(n <= 2000);

    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 1 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 1 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 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 1 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 339 ms 16908 KB Output is correct
9 Correct 322 ms 16900 KB Output is correct
10 Correct 330 ms 16832 KB Output is correct
11 Correct 352 ms 16848 KB Output is correct

Subtask #4
0 / 33.0

# Verdict Execution time Memory Grader output
1 Correct 0 ms 212 KB Output is correct
2 Correct 1 ms 212 KB Output is correct
3 Correct 0 ms 212 KB Output is correct
4 Correct 1 ms 340 KB Output is correct
5 Correct 1 ms 340 KB Output is correct
6 Correct 1 ms 340 KB Output is correct
7 Correct 1 ms 340 KB Output is correct
8 Correct 339 ms 16908 KB Output is correct
9 Correct 322 ms 16900 KB Output is correct
10 Correct 330 ms 16832 KB Output is correct
11 Correct 352 ms 16848 KB Output is correct
12 Runtime error 1238 ms 1048576 KB Execution killed with signal 9
13 Halted 0 ms 0 KB -