Submission #1171455

#	Time	Username	Problem	Language	Result	Execution time	Memory
1171455		CrabCNH	K blocks (IZhO14_blocks)	C++20	100 / 100	150 ms	3156 KiB

blocks

#include <bits/stdc++.h>

#define task   "BriantheCrab"

#define int    long long
#define pii    pair <int, int>
#define fi     first
#define se     second
#define szf    sizeof
#define sz(s)  (int)((s).size())

using namespace std;

template <class T> void mini (T &t, T f) {if (t > f) t = f;}
template <class T> void maxi (T &t, T f) {if (t < f) t = f;}

const int maxN = 1e5 + 5;
const int maxK = 1e2 + 5;
const int inf = 1e18 + 7;
const int mod = 1e9 + 7;

int n, K;
int a[maxN];

struct ST {
    int st[maxN * 4];
    
    void upd (int id, int l, int r, int pos, int val) {
        if (pos < l || pos > r) {
            return;
        }
        if (l == r) {
            st[id] = val;
            return;
        }
        int mid = (l + r) >> 1;
        upd (id * 2, l, mid, pos, val);
        upd (id * 2 + 1, mid + 1, r, pos, val);
        st[id] = max (st[id * 2], st[id * 2 + 1]);
    }
    
    int get (int id, int l, int r, int u, int v) {
        if (v < l || u > r) {
            return 0;
        }
        if (u <= l && r <= v) {
            return st[id];
        }
        int mid = (l + r) >> 1;
        int tL = get (id * 2, l, mid, u, v);
        int tR = get (id * 2 + 1, mid + 1, r, u, v);
        return max (tL, tR);
    }
} T;

namespace sub3 {   

    int dp[105][105]; // minium splited with k values in current i
    // dp i k = max (dp j k - 1 + max (ai -> aj))
    void sol () {
        for (int i = 1; i <= n; i ++) {
            cin >> a[i];
            T.upd (1, 1, n, i, a[i]);
        }
        for (int i = 0; i <= n; i ++) {
            for (int k = 1; k <= K; k ++) {
                dp[i][k] = inf;
            }
        }
        for (int i = 1; i <= n; i ++) {
            dp[i][1] = T.get (1, 1, n, 1, i);
        }
        for (int i = 1; i <= n; i ++) {
            for (int k = 2; k <= min (i, K); k ++) {
                for (int j = k; j <= i; j ++) {
                    //cout << dp[j][k - 1] << ' ' << T.get (1, 1, n, j, i) << ' ' << i << ' ' << j << ' ' << k << '\n';
                    mini (dp[i][k], dp[j - 1][k - 1] + T.get (1, 1, n, j, i));
                }
                //cout << i << ' ' << k << ' ' << dp[i][k] << '\n';
            }
        }
        cout << dp[n][K];
    }
}

namespace full {
    
    int dp[2][maxN]; // min splited 
    
    void sol () {
        for (int i = 1; i <= n; i ++) {
            cin >> a[i];
        }
        for (int i = 0; i <= n; i ++) {
            dp[0][i] = dp[1][i] = inf;
        }
        dp[0][0] = 0;
        for(int j = 1; j <= K; j ++){
            stack <int> st;
            int cur = (j & 1);
            int prev = 1 - cur;
            for (int i = 1; i <= n; i ++){
                dp[cur][i] = dp[prev][i - 1] + a[i];
                // stack duy tri duyet lai cac doan con ai max
                while(!st.empty() && a[st.top ()] <= a[i]){
                    mini (dp[cur][i], dp[prev][st.top ()] + a[i]); //  splited to new block
                    mini (dp[cur][i], dp[cur][st.top ()] - a[st.top ()] + a[i]); // optimize the cut on top upto i
                    st.pop();
                }
                if (!st.empty ()){
                    mini (dp[cur][i], dp[cur][st.top ()]); //  not splited
                }
                st.push (i);
            }
            for (int i = 0; i <= n; i++){
                dp[prev][i] = inf;
            }
        }
        cout << min (dp[0][n], dp[1][n]);
    }
}

void solve () {
    cin >> n >> K;
    if (n <= 1) {
        sub3 :: sol ();
    }
    else {
        full :: sol ();
    }
}

signed main () {
    cin.tie (nullptr) -> sync_with_stdio (false);
    if (fopen (task".inp", "r")) {
        freopen (task".inp", "r", stdin);
        freopen (task".out", "w", stdout);
    }
    int t = 1;
    //cin >> t;
    while (t --) {
        solve ();
    } 
    return 0;
}
// thfdgb

Compilation message (stderr)

blocks.cpp: In function 'int main()':
blocks.cpp:136:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  136 |         freopen (task".inp", "r", stdin);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~
blocks.cpp:137:17: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
  137 |         freopen (task".out", "w", stdout);
      |         ~~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

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