Submission #1092539

#	Time	Username	Problem	Language	Result	Execution time	Memory
1092539		K30_Thua_Phong	K blocks (IZhO14_blocks)	C++17	0 / 100	2 ms	348 KiB

blocks

#include <bits/stdc++.h>
#define ll long long
#define ii pair<ll,ll>
#define fi first
#define se second
using namespace std;
const int N = 100005;
ll n, k, amax = 0;
ll a[N + 2], dp[N + 2][150], l[N + 2];
stack <int> s;
signed main()
{
    ios_base::sync_with_stdio(false);
    cin.tie(NULL); cout.tie(NULL);
    freopen("blocks.inp", "r", stdin);
    freopen("blocks.out", "w", stdout);
    cin >> n >> k;
    for(int i = 1; i <= n; i++) {
        cin >> a[i];
        dp[i][1] = max(dp[i - 1][1], a[i]);
    }
    s.push(a[1]);
    for(int i = 2; i <= n; i++)
    {
        while(!s.empty() && a[s.top()] < a[i])
            s.pop();
        if(s.empty())
            l[i] = i;
        else
            l[i] = s.top();
        s.push(i);
    }
    for(int i = 1; i <= n; i++)
    {
        for(int d = 2; d <= k; d++)
            dp[i][d] = INT_MAX;
    }
    for(int d = 2; d <= k; d++)
    {
        for(int i = d; i <= n; i++)
        {
            amax = a[i];
            if(l[i] == i)
                for(int j = i - 1; j >= d - 1; j--)
                    dp[i][d] = min(dp[i][d], dp[j][d - 1] + a[i]);
            else {
                for(int j = i - 1; j >= l[i]; j--) {
                    dp[i][d] = min(dp[i][d], dp[j][d - 1] + amax);
                    amax = max(amax, a[j]);
                }
            }
        }
    }
    cout << dp[n][k];
    return 0;
}
/*
5 2
1 2 3 4 5
*/

Compilation message (stderr)

blocks.cpp: In function 'int main()':
blocks.cpp:15:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   15 |     freopen("blocks.inp", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
blocks.cpp:16:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   16 |     freopen("blocks.out", "w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~

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