Submission #343724

#	Time	Username	Problem	Language	Result	Execution time	Memory
343724		IZhO_2021_I_want_Silver	K blocks (IZhO14_blocks)	C++14	100 / 100	147 ms	4332 KiB

blocks

#include <iostream>
#include <algorithm>
#include <vector>
#include <cmath>
#include <set>
#include <map>
#include <iomanip>
#include <cassert>
#include <stack>
#include <queue>
#include <deque>
//#include <ext/pb_ds/assoc_container.hpp>
//#include <ext/pb_ds/tree_policy.hpp>-

using namespace std;
//using namespace __gnu_pbds;

typedef long long ll;
typedef pair <int, int> pii;
typedef pair <ll, ll> pll;

// template<typename T> using ordered_set = tree<T, null_type, less<T>, rb_tree_tag, tree_order_statistics_node_update>;
//  order_of_key (k) : Number of items strictly smaller than k .
//  find_by_order(k) : K-th element in a set (counting from zero).
#define sz(a) (int)a.size()
#define all(a) a.begin(), a.end()
#define pb push_back
#define ppb pop_back
#define mkp make_pair
#define F first
#define S second
#define lb lower_bound
#define ub upper_bound
#define show(a) cerr << #a <<" -> "<< a <<" "
#define nl cerr <<"\n"
//#define int ll

const int N = 1e5 + 5;
const int oo = 1e9 + 5;

int n, K;
vector <pll> vec;
ll dp[N][2], a[N];

void solve() {
    cin >> n >> K;
    for (int i = 1; i <= n; ++i) {
        cin >> a[i];
    }
    for (int i = 1; i <= n; ++i) {
        dp[i][0] = oo;
        dp[i][1] = oo;
    }
    for (int i = 1; i <= n; ++i) {
        dp[i][1] = max(dp[i-1][1], a[i]);
    }
    for (int k = 2; k <= K; ++k) {
        for (int i = k; i <= n; ++i) {
            ll mn = dp[i - 1][((k - 1) & 1)];
            while (sz(vec) && a[vec.back().S] <= a[i]) {
                mn = min(mn, vec.back().F);
                vec.ppb();
            }
            dp[i][(k & 1)] = mn + a[i];
            if (sz(vec)) { dp[i][(k & 1)] = min(dp[i][(k & 1)], dp[vec.back().S][(k & 1)]); }
            vec.pb({mn, i});
        }
        vec.clear();
    }
    cout << dp[n][(K & 1)];
}

 main () {
	ios_base::sync_with_stdio(false);
	cin.tie(NULL);
	int tests = 1;
	//cin >> tests;
	while (tests --) {
		solve();
	}
	return 0;
}
/*
    Just Chalish!
*/

Compilation message (stderr)

blocks.cpp:73:8: warning: ISO C++ forbids declaration of 'main' with no type [-Wreturn-type]
   73 |  main () {
      |        ^

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