Submission #1232337

#	Time	Username	Problem	Language	Result	Execution time	Memory
1232337		QuocSensei	K blocks (IZhO14_blocks)	C++20	100 / 100	318 ms	88620 KiB

blocks

#include <bits/stdc++.h>

#define ll long long
#define el cout << '\n'
#define ii pair<ll, ll>
#define fi first
#define se second

using namespace std;

const int maxn = 1e5;
const int maxk = 1e2;
const ll INF = 1e18;

int n, k;
ll a[maxn + 10], dp[maxn + 10][maxk + 10];
vector<ii> st;

int main()
{
    ios_base::sync_with_stdio(0); cin.tie(0); cout.tie(0);
    if (fopen("KBLOCK.INP", "r"))
    {
        freopen("KBLOCK.INP", "r", stdin);
        freopen("KBLOCK.OUT", "w", stdout);
    }

    cin >> n >> k;
    for (int i = 1; i <= n; i++)
        cin >> a[i];
    a[0] = INF;
    for (int j = 0; j <= k; j++)
        for (int i = 0; i <= n; i++)
            dp[i][j] = INF;
    dp[0][0] = 0;
    for (int j = 1; j <= k; j++)
    {
        st.clear();
        st.push_back({0, dp[0][j - 1]});
        for (int i = 1; i <= n; i++)
        {
            ll min_dp = dp[i - 1][j - 1];
            while (a[st.back().fi] < a[i])
            {
                min_dp = min(min_dp, st.back().se);
                st.pop_back();
            }
            dp[i][j] = min(dp[st.back().fi][j], min_dp + a[i]);
            min_dp = min(min_dp, dp[i][j - 1]);
            st.push_back({i, min_dp});
        }
    }
//    for (int j = 1; j <= k; j++)
//    {
//        for (int i = 1; i <= n; i++)
//            cout << dp[i][j] << ' ';
//        el;
//    }
    cout << dp[n][k];
}

Compilation message (stderr)

blocks.cpp: In function 'int main()':
blocks.cpp:24:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   24 |         freopen("KBLOCK.INP", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
blocks.cpp:25:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   25 |         freopen("KBLOCK.OUT", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

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