Submission #878037

#	Time	Username	Problem	Language	Result	Execution time	Memory
878037		atarii	Safety (NOI18_safety)	C++17	49 / 100	179 ms	2908 KiB

safety

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

#define ull unsigned long long
#define ll long long
#define foru(i, a, b, k) for(int i = a; i <= b; i += k)
#define umap unordered_map
#define pii pair<int, int>
#define ford(i, a, b, k) for(int i = a; i >= b; i -= k)
#define vint vector <int>
#define all(a) (a).begin(), (a).end()
#define fi first
#define se second
#define pb push_back
#define sz(s) (int)s.size()
#define ctn continue
#define ld long double

template<typename T> bool maximize(T &res, const T &val) { if (res < val){ res = val; return true; }; return false; }
template<typename T> bool minimize(T &res, const T &val) { if (res > val){ res = val; return true; }; return false; }
template<typename T> ll power(T a, const T b) { ll res = 1, x = a, y = b; while(y){if(y & 1)res *= x; x = x * x; y>>=1;}; return res; }
template<typename T> ll modpower(T a, T b, const T &m) { ll res = 1, x = a, y = b; x %= m; while(y){if(y & 1){res *= x; res %= m;}; x = x * x; x %= m; y >>= 1; } return res % m; }
template<typename T> T __lcm(T &a, T &b) { return a / __gcd(a, b) * b; }

template <typename T> bool getbit(T val, int i) { return (val >> i) & 1; }
template <typename T> int cntbit(T val)        { int cnt = 0; for( ; val; val -= val & (-val)) ++cnt; return cnt; }
template <typename T> T offbit(T val, int i) { return val & (~(T(1) << i)); }
template <typename T> T onbit(T val, int i) { return val | (T(1) << i); }

inline int readInt()       {char c;while(c=getchar(),c!='-'&&(c<'0'||c>'9'));bool sign=(c=='-');if(sign)c=getchar();int n=c-'0';while(c=getchar(),c>='0'&&c<='9')n=10*n+c-'0';return(!sign)?n:-n;}
inline ll readLong()       {char c;while(c=getchar(),c!='-'&&(c<'0'||c>'9'));bool sign=(c=='-');if(sign)c=getchar();ll  n=c-'0';while(c=getchar(),c>='0'&&c<='9')n=10*n+c-'0';return(!sign)?n:-n;}
inline string readString() {char c;while(c=getchar(),c==' '||c=='\n'||c=='\t');string s({c});while(c=getchar(),c!=EOF&&c!=' '&&c!='\n'&&c!='\t')s+=c;return s;}

template <typename _Tp> void write_unsign(const _Tp &__n) { if (__n > 9) { write_unsign(__n / 10); } putchar(__n % 10 + '0'); }
void write(const int       &__n) { if (__n < 0) { putchar('-'); write_unsign(-__n); } else { write_unsign(__n); } }
void write(const long long &__n) { if (__n < 0) { putchar('-'); write_unsign(-__n); } else { write_unsign(__n); } }
void write(const unsigned long long &__n) { if (__n < 0) { putchar('-'); write_unsign(-__n); } else { write_unsign(__n); } }
void write(const char      &__c) {                                                                putchar(__c);   }
void write(const string    &__s) { for (auto &__c : __s) {                                         putchar(__c); } }
template <typename _Tp, typename... _Ts> void write(const _Tp &__x, const _Ts &...__y) { write(__x), write(__y...); }

const  ll  MOD = 1e9 + 7;
const  ll  LIM = 1e6 + 10;
const int    N = 2e5 + 5;
const int  INF = 0x3f3f3f3f;
const  ll LINF = 1e17 + 100;
const int  LOG = 19;
const ll  base = 31;
const int offset = 1e3 + 1;

mt19937 rng(chrono::steady_clock::now().time_since_epoch().count());

inline int mul(int a, int b) { a %= MOD, b %= MOD; return 1LL * a * b % MOD; }
inline int sub(int a, int b) { a -= b; if(a < 0) a += MOD; return a; }
inline int add(int a, int b) { a += b; if(a >= MOD) a -= MOD; return a; }

int n, h;
int a[N];
int pre[N], cur[N];

void read()
{
    n = readInt();
    h = readInt();
    foru(i, 1, n, 1) a[i] = readInt();
}

namespace subtask3
{
    int p[N];

    void try0(int id, ll &minVal, ll sum)
    {
        if(id == 0) return minimize(minVal, sum), void();
        if(sum >= minVal) return;

        foru(cur, max(0, p[id + 1] - h), p[id + 1] + h, 1)
        {
            p[id] = cur;
            try0(id - 1, minVal, sum + abs(a[id] - p[id]));
        }
    }

    void try1(int id, ll &minVal, ll sum)
    {
        if(id == n + 1) return minimize(minVal, sum), void();
        if(sum >= minVal) return;

        foru(cur, max(0, p[id - 1] - h), p[id - 1] + h, 1)
        {
            p[id] = cur;
            try1(id + 1, minVal, sum + abs(a[id] - p[id]));
        }
    }

    void solve()
    {
        ll res = LINF;
        foru(i, 1, n, 1)
        {
            ll res0 = LINF, res1 = LINF;
            foru(j, 1, n, 1) p[j] = 0;
            p[i] = a[i];

            try0(i - 1, res0, 0);
            try1(i + 1, res1, 0);

            minimize(res, res0 + res1);
        }
        cout << res;
    }
}

namespace subtask4
{
    void solve()
    {
        sort(a + 1, a + 1 + n);
        ll res = 0;
        foru(i, 1, n, 1) res += abs(a[(n + 1) / 2] - a[i]);
        cout << res;
    }
}

void insert(deque <int> &q, int rb)
{
    while(!q.empty() && pre[q.back()] >= pre[rb]) q.pop_back();
    q.pb(rb);
}

void remove(deque <int> &q, int lb)
{
    while(!q.empty() && q.front() < lb) q.pop_front();
}

namespace subtask7
{
    void solve()
    {
        int liml = *min_element(a + 1, a + 1 + n);
        int limr = *max_element(a + 1, a + 1 + n);

        if(h >= *max_element(a + 1, a + 1 + n)) return cout << 0, void();

        deque <int> q; q.clear();

        foru(i, 1, n, 1)
        {
            int lb = liml, rb = min(limr, liml + h);

            q.clear();
            foru(i, lb, rb, 1)
            {
                while(!q.empty() && pre[q.back()] >= pre[i]) q.pop_back();
                q.pb(i);
            }

            foru(j, liml, limr, 1)
            {
                if(j > liml)
                {
                    if(rb + 1 <= limr) insert(q, ++rb);
                    if(j - h > liml) remove(q, ++lb);
                }
                cur[j] = abs(a[i] - j) + pre[q.front()];
            }

            foru(j, liml, limr, 1) pre[j] = cur[j];
        }

        int res = INF;
        foru(j, liml, limr, 1) minimize(res, cur[j]);
        cout << res;
    }
}

void solve()
{
    if(h == 0) return subtask4::solve();
    if(n <= 10 && h <= 2) return subtask3::solve();
    subtask7::solve();
}

signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(nullptr); cout.tie(nullptr);

    #define file "safety"
    if(fopen(file".inp", "r"))
    {
        freopen(file".inp", "r", stdin);
        freopen(file".out", "w", stdout);
    }

    read();
    solve();
    return 0;
}

Compilation message (stderr)

safety.cpp: In function 'int main()':
safety.cpp:192:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  192 |         freopen(file".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
safety.cpp:193:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  193 |         freopen(file".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 3 / 3
• Subtask 2: 4 / 4
• Subtask 3: 9 / 9
• Subtask 4: 5 / 5
• Subtask 5: 6 / 6
• Subtask 6: 11 / 11
• Subtask 7: 11 / 11
• Subtask 8: 0 / 22
• Subtask 9: 0 / 29