Submission #241342

#	Time	Username	Problem	Language	Result	Execution time	Memory
241342		kal013	Collecting Stamps 3 (JOI20_ho_t3)	C++17	100 / 100	390 ms	526968 KiB

ho_t3

/*/ Author: kal013 /*/
// #pragma GCC optimize ("O3")
#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<class T> 
using ordered_set = tree<T, null_type,less<T>, rb_tree_tag,tree_order_statistics_node_update> ;

template<class key, class value, class cmp = std::less<key>>
using ordered_map = tree<key, value, cmp, rb_tree_tag, tree_order_statistics_node_update>;
// find_by_order(k)  returns iterator to kth element starting from 0;
// order_of_key(k) returns count of elements strictly smaller than k;

struct custom_hash { // Credits: https://codeforces.com/blog/entry/62393
    static uint64_t splitmix64(uint64_t x) {
        // http://xorshift.di.unimi.it/splitmix64.c
        x += 0x9e3779b97f4a7c15;
        x = (x ^ (x >> 30)) * 0xbf58476d1ce4e5b9;
        x = (x ^ (x >> 27)) * 0x94d049bb133111eb;
        return x ^ (x >> 31);
    }

    size_t operator()(uint64_t x) const {
        static const uint64_t FIXED_RANDOM = chrono::steady_clock::now().time_since_epoch().count();
        return splitmix64(x + FIXED_RANDOM);
    }
};

template<class T> ostream& operator<<(ostream &os, vector<T> V) {
    os << "[ ";
    for(auto v : V) os << v << " ";
    return os << "]";
}
template<class T> ostream& operator<<(ostream &os, set<T> S){
    os << "{ ";
    for(auto s:S) os<<s<<" ";
    return os<<"}";
}
template<class T> ostream& operator<<(ostream &os, unordered_set<T> S){
    os << "{ ";
    for(auto s:S) os<<s<<" ";
    return os<<"}";
}
template<class T> ostream& operator<<(ostream &os, ordered_set<T> S){
    os << "{ ";
    for(auto s:S) os<<s<<" ";
    return os<<"}";
}
template<class L, class R> ostream& operator<<(ostream &os, pair<L,R> P) {
    return os << "(" << P.first << "," << P.second << ")";
}
template<class L, class R> ostream& operator<<(ostream &os, map<L,R> M) {
    os << "{ ";
    for(auto m:M) os<<"("<<m.first<<":"<<m.second<<") ";
    return os<<"}";
}
template<class L, class R> ostream& operator<<(ostream &os, unordered_map<L,R> M) {
    os << "{ ";
    for(auto m:M) os<<"("<<m.first<<":"<<m.second<<") ";
    return os<<"}";
}
template<class L, class R, class chash = std::hash<R> > ostream& operator<<(ostream &os, gp_hash_table<L,R,chash> M) {
    os << "{ ";
    for(auto m:M) os<<"("<<m.first<<":"<<m.second<<") ";
    return os<<"}";
}

#define TRACE
#ifdef TRACE
    #define trace(...) __f(#__VA_ARGS__, __VA_ARGS__)
    template <typename Arg1>
    void __f(const char* name, Arg1&& arg1){
        cerr << name << " : " << arg1 << endl;
    }
    template <typename Arg1, typename... Args>
    void __f(const char* names, Arg1&& arg1, Args&&... args){
        const char* comma = strchr(names + 1, ',');
        cerr.write(names, comma - names) << " : " << arg1<<" | ";
        __f(comma+1, args...);
    }
#else
    #define trace(...) 1
#endif

mt19937_64 rng(chrono::steady_clock::now().time_since_epoch().count());

inline int64_t random_long(long long l,long long r){
    uniform_int_distribution<int64_t> generator(l,r);
    return generator(rng);
}
inline int64_t random_long(){
    uniform_int_distribution<int64_t> generator(LLONG_MIN,LLONG_MAX);
    return generator(rng);
}


/*/---------------------------Defines----------------------/*/
typedef vector<int> vi;
typedef pair<int,int> pii;

#define ll long long
#define F first
#define S second
#define pb push_back
#define endl "\n"
#define all(v) (v).begin(),(v).end()
/*/-----------------------Modular Arithmetic---------------/*/

const int mod=1e9+7;
inline int add(int x,int y){
    x+=y;
    if (x>=mod) return x-mod;
    return x;
}
inline int sub(int x,int y){
    x-=y;
    if (x<0) return x+mod;
    return x;
}
inline int mul(int x,int y){
    return (x*1ll*y)%mod;
}
inline int power(int x,int y){
    int ans=1;
    while(y){
        if (y&1) ans=mul(ans,x);
        x=mul(x,x);
        y>>=1;
    }
    return ans;
}
inline int inv(int x){
    return power(x,mod-2);
}
/*/-----------------------------Code begins----------------------------------/*/
const int N = 405;
const int M = 205;

long long dp[N][N][2][M];
const ll INF = 1e15+10;
void solve(){
    int n;
    ll l;
    cin>>n>>l;
    vector<ll> X(2*n + 1),T(2*n + 1);
    for(int i = 0; i < n; ++i){
    	cin>>X[i];
    }
    X[n] = l;
    for(int i = 0; i<n; ++i){
    	X[n+i+1] = l + X[i];
    }


    for(int i = 0; i < n; ++i){
    	cin>>T[i];
    }
    T[n] = -1;

    for(int i = 0; i<n; ++i){
    	T[n+i+1] = T[i];
    }
    int ans = 0;

    for(int i = 0 ; i < N; ++i){
    	for(int j = 0; j < N ; ++j){
    		for(int k = 0 ; k < 2; ++k){
    			for(int l = 0; l < M; ++l){
    				dp[i][j][k][l] = INF;
    			}
    		}
    	}
    }

    dp[n][n][0][0] = 0;
    dp[n][n][1][0] = 0;
    for(int len = 1; len <= n; ++len){

    	for(int l_id = n; l_id + len >= n; --l_id){
    		int r_id = l_id + len;

    		for(int pos = 0;  pos < 2; ++pos){
    			for(int k = 0; k <= len ; ++k){
    				long long&  cur_dp = dp[l_id][r_id][pos][k];
    				cur_dp = INF;

    				if (pos == 0){
    					ll x_dif = X[l_id+1] - X[l_id];
    					cur_dp = min(dp[l_id + 1][r_id][pos][k] + x_dif, cur_dp);
    					cur_dp = min(dp[l_id+1][r_id][pos^1][k] + X[r_id] - X[l_id],cur_dp);
    					if (k >= 1 && dp[l_id+1][r_id][pos][k-1] + x_dif <= T[l_id]){
    						cur_dp = min(cur_dp,dp[l_id+1][r_id][pos][k-1] + x_dif);
    					}
    					if (k >= 1 && dp[l_id+1][r_id][pos^1][k-1] + X[r_id] - X[l_id] <= T[l_id]){
    						cur_dp = min(cur_dp, dp[l_id+1][r_id][pos^1][k-1] + X[r_id] - X[l_id]);
    					}
    				}
    				else{
    					ll x_dif = X[r_id] - X[r_id-1];
    					cur_dp = min(dp[l_id][r_id-1][pos][k] + x_dif, cur_dp);
    					cur_dp = min(dp[l_id][r_id-1][pos^1][k] + X[r_id] - X[l_id], cur_dp);

    					if (k >= 1 && dp[l_id][r_id-1][pos][k-1] + x_dif <= T[r_id]){
    						cur_dp = min(cur_dp,dp[l_id][r_id-1][pos][k-1] + x_dif);
    					}
    					if (k >= 1 && dp[l_id][r_id-1][pos^1][k-1] + X[r_id] - X[l_id] <= T[r_id]){
    						cur_dp = min(cur_dp, dp[l_id][r_id-1][pos^1][k-1] + X[r_id] - X[l_id]);
    					}	
    				}

    				if (dp[l_id][r_id][pos][k] < INF){
    					ans = max(ans,k);
    				} 

    			}
    		}
    	}
    }

    cout<<ans<<endl;
}
int main(){
    // Use "set_name".max_load_factor(0.25);"set_name".reserve(512); with unordered set
    // Or use gp_hash_table<X,null_type>
    ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
    cout<<fixed<<setprecision(25);
    cerr<<fixed<<setprecision(10);
    auto start = std::chrono::high_resolution_clock::now();
    int t=1;
    // cin>>t;
    while(t--) {
        solve();
    }
    auto stop = std::chrono::high_resolution_clock::now(); 
    auto duration = std::chrono::duration_cast<std::chrono::nanoseconds>(stop - start); 
    
    // cerr << "Time taken : " << ((long double)duration.count())/((long double) 1e9) <<"s "<< endl;     
}

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