Submission #1110034

#	Time	Username	Problem	Language	Result	Execution time	Memory
1110034		cpptowin	K blocks (IZhO14_blocks)	C++17	53 / 100	1045 ms	15172 KiB

blocks

#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 inf (int)1e9
#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;
    int n;
    /// real n
    SegmentTree(int _n = 0) : n(_n)
    {
        st.resize(4 * n + 10, inf);
    }
    void resize(int _n)
    {
        n = _n;
        st.resize(4 * n + 10, inf);
    }
    void update(int id, int l, int r, int x, int val)
    {
        if (x > r or x < l)
            return;
        if (l == r)
        {
            st[id] += val;
            return;
        }
        int mid = (l + r) >> 1;
        update(id << 1, l, mid, x, val);
        update(id << 1 | 1, mid + 1, r, x, val);
        st[id] = min(st[id << 1], st[id << 1 | 1]);
    }
    void assign(int id, int l, int r, int x, int val)
    {
        if (x > r or x < l)
            return;
        if (l == r)
        {
            st[id] = val;
            return;
        }
        int mid = (l + r) >> 1;
        assign(id << 1, l, mid, x, val);
        assign(id << 1 | 1, mid + 1, r, x, 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];
        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 x, int val)
    {
        update(1, 1, n, x, val);
    }
    void assign(int x, int val)
    {
        assign(1, 1, n, x, val);
    }
};
int n, k, a[maxn];
int l[maxn], r[maxn], f[2][maxn];
void L(int a[], int n, int ans[])
{
    stack<int> st;
    fo(i, 1, n)
    {
        while (st.size() and a[st.top()] <= a[i])
            st.pop();
        ans[i] = (st.empty() ? 0 : st.top());
        st.push(i);
    }
}
void R(int a[], int n, int ans[])
{
    stack<int> st;
    fod(i, n, 1)
    {
        while (st.size() and a[st.top()] <= a[i])
            st.pop();
        ans[i] = (st.empty() ? n + 1 : st.top());
        st.push(i);
    }
}
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 >> k;
    fo(i, 1, n) cin >> a[i];
    L(a, n, l);
    R(a, n, r);
    int maxx = 0;
    fo(i,1,n) maximize(maxx,a[i]),f[1][i] = maxx;
    fo(j, 2, k)
    {
        SegmentTree st(n);
        priority_queue<pii,vii,greater<pii>> q;
        fo(i, 1, n)
        {
            f[j & 1][i] = st.get(l[i], i - 1) + a[i];
            while(ss(q) and q.top().se < i) q.pop();
            if(ss(q))
            minimize(f[j & 1][i],q.top().fi);
            st.assign(i,f[j & 1 ^ 1][i]);
            q.push({f[j & 1][i],r[i] - 1});
        }
    }
    int ans = inf;
    fod(i, n, 1) if (r[i] == n + 1) minimize(ans, f[k & 1][i]);
    cout << ans;
}

Compilation message (stderr)

blocks.cpp:147:1: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
  147 | main()
      | ^~~~
blocks.cpp: In function 'int main()':
blocks.cpp:173:29: warning: suggest parentheses around arithmetic in operand of '^' [-Wparentheses]
  173 |             st.assign(i,f[j & 1 ^ 1][i]);
      |                           ~~^~~
blocks.cpp:152:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  152 |         freopen(name ".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
blocks.cpp:153:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  153 |         freopen(name ".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~

• Subtask 1: 14 / 14
• Subtask 2: 18 / 18
• Subtask 3: 21 / 21
• Subtask 4: 0 / 47