Submission #369170

#	Time	Username	Problem	Language	Result	Execution time	Memory
369170		wiwiho	Collecting Stamps 3 (JOI20_ho_t3)	C++14	100 / 100	263 ms	130412 KiB

ho_t3

#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 iceil(a, b) (((a) + (b) - 1) / (b))
#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 = 1LL << 60;

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

int n;
ll L;
vector<ll> x;

ll dis(int a, int b){
    if(a > b) swap(a, b);
    return min(x[b] - x[a], L - x[b] + x[a]);
}

int main(){
    StarBurstStream

    cin >> n >> L;
    x.resize(n + 1);
    for(int i = 1; i <= n; i++) cin >> x[i];
    vector<ll> t(n + 1);
    for(int i = 1; i <= n; i++) cin >> t[i];

    vector<vector<vector<ll>>> dpl(n + 1, vector<vector<ll>>(n + 1, vector<ll>(n + 1, MAX)));
    vector<vector<vector<ll>>> dpr(n + 1, vector<vector<ll>>(n + 1, vector<ll>(n + 1, MAX)));
    dpl[0][0][0] = 0;
    dpr[0][0][0] = 0;

    for(int len = 1; len <= n; len++){
        for(int l = 0; l <= n; l++){
            int r = (l + len) % (n + 1);
            if(l < r && l != 0) continue;

            int tl = (l + 1) % (n + 1);
            int tr = (r - 1 + n + 1) % (n + 1);
//            cerr << l << " "<< r << " " << tl << " " << tr << "\n";

            for(int k = 0; k <= n; k++){
                if(k && dpl[tl][r][k - 1] + dis(tl, l) <= t[l]) dpl[l][r][k] = min(dpl[l][r][k], dpl[tl][r][k - 1] + dis(tl, l));
                if(k && dpr[tl][r][k - 1] + dis(r, l) <= t[l]) dpl[l][r][k] = min(dpl[l][r][k], dpr[tl][r][k - 1] + dis(r, l));
                dpl[l][r][k] = min({dpl[l][r][k], dpl[tl][r][k] + dis(tl, l), dpr[tl][r][k] + dis(r, l)});

                if(k && dpl[l][tr][k - 1] + dis(l, r) <= t[r]) dpr[l][r][k] = min(dpr[l][r][k], dpl[l][tr][k - 1] + dis(l, r));
                if(k && dpr[l][tr][k - 1] + dis(tr, r) <= t[r]) dpr[l][r][k] = min(dpr[l][r][k], dpr[l][tr][k - 1] + dis(tr, r));
                dpr[l][r][k] = min({dpr[l][r][k], dpl[l][tr][k] + dis(l, r), dpr[l][tr][k] + dis(tr, r)});
            }
        }
    }

//    for(int i = 0; i <= n; i++){
//        for(int j = 0; j <= n; j++){
//            cerr << i << " " << j << "\n";
//            printv(dpl[i][j], cerr);
//            printv(dpr[i][j], cerr);
//        }
//    }

    int ans = 0;
    for(int i = 1; i <= n; i++){
        for(int j = 0; j <= n; j++){
            for(int k = 0; k <= n; k++){
                if(dpl[j][k][i] < MAX || dpr[j][k][i] < MAX) ans = i;
            }
        }
    }
    cout << ans << "\n";

    return 0;
}

• Subtask 1: 5 / 5
• Subtask 2: 10 / 10
• Subtask 3: 10 / 10
• Subtask 4: 75 / 75