Submission #907609

#	Time	Username	Problem	Language	Result	Execution time	Memory
907609		vjudge1	Let's Win the Election (JOI22_ho_t3)	C++17	0 / 100	2566 ms	2396 KiB

Main

#pragma GCC target ("avx2")
#pragma GCC optimize ("O3")
#pragma GCC optimize ("unroll-loops")

#include<bits/stdc++.h>
#include<math.h>
using namespace std;

typedef int ll;
typedef float ld;
typedef pair<ll, ll> pl;
typedef vector<ll> vl;
#define FD(i, r, l) for(ll i = r; i > (l); --i)

#define K first
#define V second
#define G(x) ll x; cin >> x;
#define GD(x) ld x; cin >> x;
#define GS(s) string s; cin >> s;
#define EX(x) { cout << x << '\n'; exit(0); }
#define A(a) (a).begin(), (a).end()
#define F(i, l, r) for (ll i = l; i < (r); ++i)

#define NN 510
#define M 1000000007 // 998244353

vector<pl> votes;
ll n, k;
ll take;

ld dp[2][NN][NN]; // 
ll op, np;

ld rec(ll i, ll bs, ll vots, bool old) {
    if (i == n) return vots + bs >= k and bs >= take ? 0: 1e9;
    if (old) return dp[op][bs][vots];
    auto &DP = dp[np][bs][vots];
    DP = 1e9;
    DP = min(DP, rec(i+1, bs, vots, 1)); 
    DP = min(DP, rec(i+1, bs, vots+1, 1) + ld(votes[i].V)/(1 + take)); 
    if (~votes[i].K) DP = min(DP, rec(i+1, bs+1, vots, 1) + ld(votes[i].K)/(1 + bs)); 
    return DP;
}

ld cache[510];

ld q(ll idx) {
    take = idx;
    if (idx < 0 || idx > n) return 1e9;
    if (cache[idx] == cache[idx]) return cache[idx];
    op = 0, np = 1;
    FD(i, n-1, -1) {
        F(bs, 0, n+1) F(vots, 0, n+1) rec(i, bs, vots, 0);    
        swap(op, np);
    }

    auto ans = dp[op][0][0];

    // cout << idx << "WTF " << ans << endl;

    return cache[idx] = ans;
}

int main(){
//    freopen("a.in", "r", stdin);
//    freopen("a.out", "w", stdout);

    ios_base::sync_with_stdio(false); cin.tie(0);
    cout << fixed << setprecision(20);
    cin >> n >> k;
    votes.resize(n);
    for (auto &[b, a]: votes) {
        cin >> a >> b;
    }
    memset(cache, -1, sizeof cache);
    sort(A(votes));
    ld ans = 1e9; 

    ll l = -1, r = n;
    while (l+1<r) {
        ll mid = (l+r)/2;
        if (q(mid) < q(mid+1)) l = mid;
        else r = mid;
    }
    F(th, l-2, l+3) ans = min(ans, q(th));
    // F(i, 0, n+1) ans = min(ans, q(i));

    cout << ans << endl;

}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 5
• Subtask 3: 0 / 11
• Subtask 4: 0 / 12
• Subtask 5: 0 / 33
• Subtask 6: 0 / 11
• Subtask 7: 0 / 23