#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
const int N = 1e5 + 5;
const ll INF = 1e18 + 7;
ll dp[N][3], n, k, a[N], st[4 * N];
void update(int id, int l, int r, int pos, ll val)
{
if (l > r || pos < l || r < pos) return ;
if (l == r)
{
st[id] = val;
return ;
}
int mid = (l + r) / 2;
if (pos <= mid) update(id * 2, l, mid, pos, val);
else update(id * 2 + 1, mid + 1, r, pos, val);
st[id] = min(st[id * 2], st[id * 2 + 1]);
}
int main()
{
std::ios_base::sync_with_stdio(0); cin.tie(0);
freopen("blocks.in", "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]);
for (int i = 1; i<=4*n; i++) st[i] = INF;
for (int j = 2; j<=k; j++)
{
stack<pair<int, ll>> st;
int cur = k & 1;
for (int i = j; i<=n; i++)
{
ll minF = dp[i - 1][1 - cur];
while (s.size() && a[s.top().first] <= a[i])
update(1, 1, n, s.top().first, INF), minF = min(minF, s.top().second), s.pop_back();
dp[i][cur] = min(st[1], minF + a[i]);
update(1, 1, n, i, dp[i][cur]);
s.push_back({i, minF});
}
}
//for (int i = 2; i<=n; i++) cout<<dp[i][k & 1]<<' ';
cout<<dp[n][k & 1];
return 0;
}
Compilation message
blocks.cpp: In function 'int main()':
blocks.cpp:38:20: error: 's' was not declared in this scope
38 | while (s.size() && a[s.top().first] <= a[i])
| ^
blocks.cpp:40:32: error: no match for 'operator[]' (operand types are 'std::stack<std::pair<int, long long int> >' and 'int')
40 | dp[i][cur] = min(st[1], minF + a[i]);
| ^
blocks.cpp:42:13: error: 's' was not declared in this scope
42 | s.push_back({i, minF});
| ^
blocks.cpp:26:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
26 | freopen("blocks.in", "r", stdin);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~
blocks.cpp:27:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
27 | freopen("blocks.out", "w", stdout);
| ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~
