Submission #1019021

#	Time	Username	Problem	Language	Result	Execution time	Memory
1019021		GrindMachine	Homecoming (BOI18_homecoming)	C++17	0 / 100	1062 ms	35676 KiB

homecoming

#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>

using namespace std;
using namespace __gnu_pbds;

template<typename T> using Tree = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
typedef long long int ll;
typedef long double ld;
typedef pair<int,int> pii;
typedef pair<ll,ll> pll;

#define fastio ios_base::sync_with_stdio(false); cin.tie(NULL)
#define pb push_back
#define endl '\n'
#define sz(a) (int)a.size()
#define setbits(x) __builtin_popcountll(x)
#define ff first
#define ss second
#define conts continue
#define ceil2(x,y) ((x+y-1)/(y))
#define all(a) a.begin(), a.end()
#define rall(a) a.rbegin(), a.rend()
#define yes cout << "Yes" << endl
#define no cout << "No" << endl

#define rep(i,n) for(int i = 0; i < n; ++i)
#define rep1(i,n) for(int i = 1; i <= n; ++i)
#define rev(i,s,e) for(int i = s; i >= e; --i)
#define trav(i,a) for(auto &i : a)

template<typename T>
void amin(T &a, T b) {
    a = min(a,b);
}

template<typename T>
void amax(T &a, T b) {
    a = max(a,b);
}

#ifdef LOCAL
#include "debug.h"
#else
#define debug(...) 42
#endif

/*

refs:
edi

*/

const int MOD = 1e9 + 7;
const int N = 1e5 + 5;
const int inf1 = int(1e9) + 5;
const ll inf2 = ll(1e18) + 5;

#include "homecoming.h"

ll solve(int n, int k, int *A, int *B){
    vector<int> a(2*n+5), b(2*n+5);
    rep(i,2*n) a[i+1] = A[i%n], b[i+1] = B[i%n];

    vector<ll> pb(2*n+5);
    rep1(i,2*n) pb[i] = pb[i-1]+b[i];

    vector<ll> cost1(2*n+5), cost2(2*n+5);
    rep1(i,2*n){
        if(i+k-1 > 2*n) break;
        ll s = pb[i+k-1]-pb[i-1];
        cost1[i] = a[i]-s;
        cost2[i] = a[i]-b[i+k-1];
    }

    // all subjects win (so all books taken)
    ll all_win = 0;
    rep1(i,n) all_win += a[i]-b[i];

    ll ans = all_win;

    // at least 1 subject doesnt win (so at least 1 book not taken)
    rep1(f,n){
        // f = first book not taken
        ll dp1[2], dp2[2];
        memset(dp1,-0x3f,sizeof dp1);
        memset(dp2,-0x3f,sizeof dp2);
        dp1[0] = 0;

        for(int i = f+1; i+k-1 < f+n; ++i){
            amax(dp2[0],dp1[0]);
            amax(dp2[1],dp1[0]+cost1[i]);
            amax(dp2[1],dp1[1]+cost2[i]);
            amax(dp2[0],dp1[1]);

            rep(j,2){
                dp1[j] = dp2[j];
                dp2[j] = -inf2;
            }
        }

        amax(ans,dp1[0]);
    }

    return ans;
}

• Subtask 1: 0 / 13
• Subtask 2: 0 / 18
• Subtask 3: 0 / 31
• Subtask 4: 0 / 38