Submission #1153018

#	Time	Username	Problem	Language	Result	Execution time	Memory
1153018		icebear	K blocks (IZhO14_blocks)	C++20	100 / 100	127 ms	8392 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], rmq[18][N];

int getMin(int l, int r) {
    int k = 31 - __builtin_clz((r - l + 1));
    if (l > r) return inf;
    return min(rmq[k][l], rmq[k][r - MASK(k) + 1]);
}

void buildRMQ(int cur) {
    FOR(i, 0, n) rmq[0][i] = dp[cur][i];
    FOR(j, 1, 17) FOR(i, 0, n - MASK(j) + 1)
        rmq[j][i] = min(rmq[j - 1][i], rmq[j - 1][i + MASK(j - 1)]);
}

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) {
    FOR(j, 2, k) {
        int cur = j & 1;
        int old = cur ^ 1;
        buildRMQ(old);
        dp[cur][0] = inf;
        FOR(i, 1, n) {
            dp[cur][i] = inf;
            minimize(dp[cur][i], getMin(pos[i] - 1, i - 1) + a[i]);
            minimize(dp[cur][i], dp[cur][pos[i] - 1]);
        }
    }

    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:85:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   85 |         freopen(task".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
blocks.cpp:86:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   86 |         freopen(task".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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