Submission #1185846

#	Time	Username	Problem	Language	Result	Execution time	Memory
1185846		Celebi_276	K blocks (IZhO14_blocks)	C++20	100 / 100	129 ms	2960 KiB

blocks

#include <bits/stdc++.h>
using namespace std;
const int N = 1E5 + 15;
long long dp[N][2];
int a[N], n, k;
bool pre, cur;
int32_t main () {
    scanf("%d%d", &n, &k);
    for (int i = 1; i <= n; i++) {
        scanf("%d", &a[i]);
        dp[i][1] = max(dp[i - 1][1], 1LL * a[i]);
    }
    dp[0][1] = 1E18;
    pre = 1; cur = !pre;
    for (int j = 2; j <= k; j++) {
        for (int i = 0; i <= n; i++) dp[i][cur] = 0;
        stack <pair <int, long long>> T;
        for (int i = 0; i < j; i++) dp[i][cur] = 1e18;
        for (int i = j; i <= n; i++) {
            long long cur_mn = dp[i - 1][pre];
            while (T.size() && a[T.top().first] <= a[i]) {
                cur_mn = min(cur_mn, T.top().second);
                T.pop();
            }
            dp[i][cur] = cur_mn + a[i];
            if (T.size()) dp[i][cur] = min(dp[i][cur], dp[T.top().first][cur]);
            T.emplace(i, cur_mn);
        }
        swap(cur, pre);
    }
    printf("%lld\n", dp[n][pre]);
}

Compilation message (stderr)

blocks.cpp: In function 'int32_t main()':
blocks.cpp:8:10: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
    8 |     scanf("%d%d", &n, &k);
      |     ~~~~~^~~~~~~~~~~~~~~~
blocks.cpp:10:14: warning: ignoring return value of 'int scanf(const char*, ...)' declared with attribute 'warn_unused_result' [-Wunused-result]
   10 |         scanf("%d", &a[i]);
      |         ~~~~~^~~~~~~~~~~~~

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