Submission #1198760

#	Time	Username	Problem	Language	Result	Execution time	Memory
1198760		4o2a	K blocks (IZhO14_blocks)	C++17	100 / 100	450 ms	82344 KiB

blocks

#include <bits/stdc++.h>
#define pb push_back
#define fi first
#define se second
#define _F "test"
using namespace std;
typedef long long ll;

constexpr ll INF = 1e18;
int n, k;
ll st[200001];

void upd(int pos, ll val)
{
    for (st[pos += n] = val; pos > 1; pos >>= 1)
        st[pos>>1] = min(st[pos], st[pos^1]);
}

ll getmin(int l, int r)
{
    ll res = INF;
    for (l += n, r += n; l < r; l >>= 1, r >>= 1)
    {
        if (l&1)
            res = min(res, st[l++]);
        if (r&1)
            res = min(res, st[--r]);
    }
    return res;
}

void solve()
{
    cin>>n>>k;
    vector<int> val(n+1), pre(n+1); val[0] = 10000000;
    stack<int> temp; temp.push(0);
    vector<vector<ll>> dp(k+1, vector<ll>(n+1, INF)); dp[0][0] = 0;
    for (int i = 1; i <= n; ++i)
    {
        cin>>val[i];
        while (val[i] >= val[temp.top()])
            temp.pop();
        pre[i] = temp.top();
        temp.push(i);
    }
    dp[1][1] = val[1];
    for (int i = 2; i <= n; ++i)
        dp[1][i] = max(dp[1][i-1], (ll)val[i]);
    for (int i = 2; i <= k; ++i)
    {
        for (int j = 1; j <= n; ++j)
            upd(j, val[j] + dp[i-2][j-1]);
        for (int j = i; j <= n; ++j)
        {
            dp[i][j] = min({dp[i][pre[j]],
                            dp[i-1][j-1] + val[j],
                            val[j] + getmin(pre[j]+1, j)});
        }
    }
    cout<<dp[k][n];
}

int main()
{
    if (fopen(_F".INP", "r"))
    {
        freopen(_F".INP", "r", stdin);
        //freopen(_F".OUT", "w", stdout);
    }
    ios_base::sync_with_stdio(0);
    cin.tie(0);
    int Test = 1; //cin>>Test;
    while (Test--) solve();
}

Compilation message (stderr)

blocks.cpp: In function 'int main()':
blocks.cpp:67:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   67 |         freopen(_F".INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~

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