Submission #1122755

#	Time	Username	Problem	Language	Result	Execution time	Memory
1122755		gdragon	K blocks (IZhO14_blocks)	C++20	100 / 100	325 ms	44184 KiB

blocks

#include <bits/stdc++.h>
using namespace std;
#define TASK "long"
#define fi first
#define se second
#define ll long long
#define pb push_back
#define ALL(x) (x).begin(), (x).end()
#define GETBIT(mask, i) ((mask) >> (i) & 1)
#define MASK(i) ((1LL) << (i))
#define SZ(x) ((int)(x).size())
#define mp make_pair
#define CNTBIT(mask) __builtin_popcount(mask)
template<class X, class Y> bool maximize(X &x, Y y){ if (x < y) {x = y; return true;} return false;};
template<class X, class Y> bool minimize(X &x, Y y){ if (x > y) {x = y; return true;} return false;};
typedef pair<int, int> ii;
const int N = 1e5 + 5;
const int inf = 1e9 + 7;
const long long INF = (long long)1e18 + 7;
const int mod = 1e9 + 7;
void add(int &x, int y) {x += y; if (x >= mod) x -= mod;}
void sub(int &x, int y) {x -= y; if (x < 0) x += mod;}
int mul(int x, int y) {return 1LL * x * y % mod;}
// -----------------------------------------//
const int LOG = 17;
int n, k;
int f[N][LOG + 2], a[N];
void read() {
    cin >> n >> k;
    for(int i = 1; i <= n; i++) cin >> a[i];
}
void build() {
    for(int i = 1; i <= n; i++) f[i][0] = a[i];
    for(int j = 1; j <= LOG; j++) {
        for(int i = 1; i + MASK(j) - 1 <= n; i++) f[i][j] = max(f[i][j - 1], f[i + MASK(j - 1)][j - 1]);
    }
}
int getMax(int l, int r) {
    int k = log2(r - l + 1);
    return max(f[l][k], f [r - MASK(k) + 1][k]);
}

void sub3() {
    vector<vector<int>> dp;
    dp.assign(n + 2, vector<int>(k + 2, inf));
    dp[0][0] = 0;
    for(int i = 1; i <= n; i++) {
        for(int j = 1; j <= min(k, i); j++) {
            int mx = a[i];
            for(int p = i; p >= 1; p--) {
                mx = max(mx, a[p]);
                minimize(dp[i][j], dp[p - 1][j - 1] + mx);
            }
        }
    }
    cout << dp[n][k];
}
void solve() {
    // if (n <= 100) {
    //     sub3();
    //     return;
    // }
    vector<vector<int>> dp;
    dp.assign(n + 2, vector<int>(k + 2, inf));
    dp[0][0] = 0;
    a[0] = inf;
    for(int j = 1; j <= k; j++) {
        stack<int> st;
        st.push(0);
        for(int i = 1; i <= n; i++) {
            int best = dp[i - 1][j - 1] + a[i], pos = i;
            while(!st.empty() && a[st.top()] <= a[i]) {
                if (minimize(best, dp[st.top() - 1][j - 1] + a[i])) {
                    pos = st.top();
                }
                st.pop();
            }
            if (st.top() > 0) {
                minimize(best, dp[st.top()][j]);
                minimize(best, dp[st.top()][j - 1] + a[i]);
            }
            // cerr << i << ' ' << j << ' ' << best << ' ' << pos << ' ' << st.top() << endl;
            dp[i][j] = best;
            st.push(pos);
            st.push(i);
        }
    }
    cout << dp[n][k];
}
signed 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 test = 1;
    // cin >> test;
    while(test--) {
        read();
        solve();
    }
    return 0;
}

Compilation message (stderr)

blocks.cpp: In function 'int main()':
blocks.cpp:93:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   93 |         freopen(TASK".inp", "r", stdin);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
blocks.cpp:94:16: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   94 |         freopen(TASK".out", "w", stdout);
      |         ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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