Submission #1114362

#	Time	Username	Problem	Language	Result	Execution time	Memory
1114362		cpptowin	The short shank; Redemption (BOI21_prison)	C++17	55 / 100	621 ms	524288 KiB

prison

#include <bits/stdc++.h>
#define fo(i, d, c) for (int i = d; i <= c; i++)
#define fod(i, c, d) for (int i = c; i >= d; i--)
#define maxn 1000010
#define N 1010
#define fi first
#define se second
#define pb emplace_back
#define en cout << "\n";
#define int long long
#define inf (int)1e18
#define bitcount(x) __builtin_popcountll(x)
#define pii pair<int, int>
#define vii vector<pii>
#define lb(x) x & -x
#define bit(i, j) ((i >> j) & 1)
#define offbit(i, j) (i ^ (1LL << j))
#define onbit(i, j) (i | (1LL << j))
#define vi vector<int>
#define all(x) x.begin(), x.end()
#define ss(x) (int)x.size()
#define UNIQUE(v) v.erase(unique(all(v)),v.end())
template <typename T1, typename T2>
bool minimize(T1 &a, T2 b)
{
    if (a > b)
    {
        a = b;
        return true;
    }
    return false;
}
template <typename T1, typename T2>
bool maximize(T1 &a, T2 b)
{
    if (a < b)
    {
        a = b;
        return true;
    }
    return false;
}
using namespace std;
const int nsqrt = 450;
const int mod = 1e9 + 7;
void add(int &x, int k)
{
    x += k;
    x %= mod;
    if(x < 0) x += mod;
}
void del(int &x, int k)
{
    x -= k;
    x %= mod;
    if(x < 0) x += mod;
}
struct SegmentTree
{
    vector<int> st, lazy;
    int n;
    /// real n
    SegmentTree(int _n = 0) : n(_n)
    {
        st.resize(4 * n + 10);
        lazy.resize(4 * n + 10);
    }
    void down(int id, int l, int r)
    {
        st[id << 1] += lazy[id];
        lazy[id << 1] += lazy[id];
        st[id << 1 | 1] += lazy[id];
        lazy[id << 1 | 1] += lazy[id];
        lazy[id] = 0;
    }

    void update(int id, int l, int r, int u, int v, int val)
    {
        if (u > r || l > v)
            return;
        if (u <= l && r <= v)
        {
            st[id] += val;
            lazy[id] += val;
            return;
        }
        down(id, l, r);
        int mid = (l + r) >> 1;
        update(id << 1, l, mid, u, v, val);
        update(id << 1 | 1, mid + 1, r, u, v, val);
        st[id] = min(st[id << 1], st[id << 1 | 1]);
    }

    int get(int id, int l, int r, int u, int v)
    {
        if (l > v || u > r)
            return inf;
        if (u <= l && r <= v)
            return st[id];
        down(id, l, r);
        int mid = (l + r) >> 1;
        return min(get(id << 1, l, mid, u, v), get(id << 1 | 1, mid + 1, r, u, v));
    }
    int get(int l, int r)
    {
        return get(1, 1, n, l, r);
    }
    void update(int l, int r, int val)
    {
        update(1, 1, n, l, r, val);
    }
};
int n,d,t;
int a[maxn];
vi nen;
namespace sub4 
{
    struct BIT
    {
        int t[maxn];
        BIT()
        {
            memset(t,-1,sizeof t);
        }
        void up(int x,int val)
        {
            for( ; x < maxn ; x += lb(x)) maximize(t[x],val);
        }
        int get(int x)
        {
            int ans = -1;
            for( ; x ; x -= lb(x)) maximize(ans,t[x]);
            return ans;
        }
    }tree;
    vector<vi> f;
    int l[maxn];
    void solve()
    {
        fo(i,1,n) 
        {
            nen.pb(a[i] - i);
            nen.pb(t - i);
        }
        sort(all(nen));
        UNIQUE(nen);
        fo(i,1,n) 
        {
            int lb = lower_bound(all(nen),t - i) - nen.begin() + 1;
            l[i] = tree.get(lb);
            if(a[i] <= t) l[i] = i;
            lb = lower_bound(all(nen),a[i] - i) - nen.begin() + 1;
            tree.up(lb,i);
        }
        f.resize(n + 5,vi(d + 5,inf));
        f[0][0] = 0;
        fo(i,1,n) 
        {
            f[i][0] = f[i - 1][0] + (l[i] != -1); 
        }
        fo(j,1,d) 
        {
            SegmentTree st(n);
            fo(i,1,n) 
            {
                st.update(i,i,f[i - 1][j - 1]);
                if(l[i] != -1) st.update(1,l[i],1);
                f[i][j] = st.get(1,i);
            }
        }
        cout << f[n][d];
    }
}
main()
{
#define name "TASK"
    if (fopen(name ".inp", "r"))
    {
        freopen(name ".inp", "r", stdin);
        freopen(name ".out", "w", stdout);
    }
    ios_base::sync_with_stdio(false);
    cin.tie(NULL);
    cin >> n >> d >> t;
    fo(i,1,n) cin >> a[i];
    sub4::solve();
}

Compilation message (stderr)

prison.cpp:174:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  174 | main()
      | ^~~~
prison.cpp: In function 'int main()':
prison.cpp:179:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  179 |         freopen(name ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
prison.cpp:180:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  180 |         freopen(name ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 15 / 15
• Subtask 2: 10 / 10
• Subtask 3: 20 / 20
• Subtask 4: 10 / 10
• Subtask 5: 0 / 25
• Subtask 6: 0 / 20