Submission #1153017

#	Time	Username	Problem	Language	Result	Execution time	Memory
1153017		icebear	K blocks (IZhO14_blocks)	C++20	14 / 100	0 ms	328 KiB

blocks

// ~~ icebear love attttttt ~~
#include <bits/stdc++.h>
using namespace std;

typedef long long ll;
typedef pair<int, int> ii;
typedef pair<int, ii> iii;

template<class T>
    bool minimize(T &a, const T &b) {
        if (a > b) return a = b, true;
        return false;
    }

template<class T>
    bool maximize(T &a, const T &b) {
        if (a < b) return a = b, true;
        return false;
    }

#define FOR(i,a,b) for(int i=(a); i<=(b); ++i)
#define FORR(i,a,b) for(int i=(a); i>=(b); --i)
#define REP(i, n) for(int i=0; i<(n); ++i)
#define RED(i, n) for(int i=(n)-1; i>=0; --i)
#define MASK(i) (1LL << (i))
#define BIT(S, i) (((S) >> (i)) & 1)
#define mp make_pair
#define pb push_back
#define fi first
#define se second
#define all(x) x.begin(), x.end()
#define task "icebearat"

const int MOD = 1e9 + 7;
const int inf = 1e9 + 27092008;
const ll INF = 1e18 + 27092008;
const int N = 2e5 + 5;
int n, k, a[N], pos[N];
int dp[2][N];

struct ArpaTrick {
    int par[N];
    int root(int v) {
        return (par[v] == v ? v : par[v] = root(par[v]));
    }
} dsu;

void init(void) {
    cin >> n >> k;
    FOR(i, 1, n) cin >> a[i], dp[1][i] = max(dp[1][i - 1], a[i]);
    dp[1][0] = inf;
    stack<int> st;
    FOR(i, 1, n) {
        while(!st.empty() && a[st.top()] <= a[i]) st.pop();
        pos[i] = (st.empty() ? 1 : st.top() + 1);
        st.push(i);
    }
}

void process(void) {
    stack<int> st;
    FOR(j, 2, k) {
        int cur = j & 1;
        int old = cur ^ 1;
        dp[cur][0] = inf;
        while(!st.empty()) st.pop();
        FOR(i, 1, n) dsu.par[i] = i;
        st.push(0);
        FOR(i, 1, n) {
            dp[cur][i] = inf;
            minimize(dp[cur][i], dp[old][dsu.root(pos[i] - 1)] + a[i]);
            minimize(dp[cur][i], dp[cur][pos[i] - 1]);

            while(!st.empty() && dp[old][st.top()] > dp[old][i]) {
                dsu.par[st.top()] = i;
                st.pop();
            }
            st.push(i);
        }
    }

    cout << dp[k & 1][n];
}

int main() {
    ios_base::sync_with_stdio(0);
    cin.tie(0); cout.tie(0);
    if (fopen(task".inp", "r")) {
        freopen(task".inp", "r", stdin);
        freopen(task".out", "w", stdout);
    }
    int tc = 1;
//    cin >> tc;
    while(tc--) {
        init();
        process();
    }
    return 0;
}

Compilation message (stderr)

blocks.cpp: In function 'int main()':
blocks.cpp:89:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   89 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
blocks.cpp:90:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   90 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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