Submission #343059

#	Time	Username	Problem	Language	Result	Execution time	Memory
343059		dxz05	Bigger segments (IZhO19_segments)	C++14	27 / 100	146 ms	163436 KiB

segments

//#pragma GCC optimize("Ofast")

#include <bits/stdc++.h>

using namespace std;

void debug_out() { cerr << endl; }

template<typename Head, typename... Tail>
void debug_out(Head H, Tail... T) {
    cerr << "[" << H << "]";
    debug_out(T...);
}

#ifdef dddxxz
#define debug(...) cerr << "[" << #__VA_ARGS__ << "]:", debug_out(__VA_ARGS__)
#else
#define debug(...) 42
#endif

#define SZ(s) ((int)s.size())

clock_t startTime;

double getCurrentTime() {
    return (double) (clock() - startTime) / CLOCKS_PER_SEC;
}

typedef long long ll;
//mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
const double eps = 0.00001;
const int MOD = 1e9 + 7;
const int INF = 1000000101;
const long long LLINF = 1223372000000000555;
const int N = 1e6 + 4e4;
const int M = 3201;
const int L = 19;

ll a[M];
ll dp[M][M];
ll pref[M];

ll get(int l, int r){
    if (l > r) return 0;
    return pref[r] - pref[l - 1];
}

struct SegTree{
    int size = 1;
    int idx = 1;

    vector<ll> tree;

    void build(int v, int tl, int tr){
        if (tl == tr){
            tree[v] = dp[tl][idx] + get(1, tl);
            return;
        }
        int tm = (tl + tr) >> 1;
        build(v + v, tl, tm);
        build(v + v + 1, tm + 1, tr);
        tree[v] = min(tree[v + v], tree[v + v + 1]);
    }

    void init(int n, int x){
        idx = x;
        while (size < n) size *= 2;
        tree.resize(size * 2);
        build(1, 1, size);
    }

    int find(int v, int tl, int tr, ll val){
        if (tl == tr) return tl;
        int tm = (tl + tr) >> 1;
        if (tree[v + v + 1] <= val) return find(v + v + 1, tm + 1, tr, val);
        if (tree[v + v] <= val) return find(v + v, tl, tm, val);
        return 0;
    }

    int find(ll x){
        return find(1, 1, size, x);
    }

} st[M];

void solve(int TC) {
    int n;
    cin >> n;

    for (int i = 1; i <= n; i++){
        cin >> a[i];
        pref[i] = pref[i - 1] + a[i];
    }

    for (auto & i : dp) for (long long & j : i) j = LLINF;

    dp[0][0] = 0;
    for (int j = 1; j <= n; j++){
        if (j == 1){
            for (int i = 1; i <= n; i++){
                dp[i][j] = get(1, i);
            }
        } else {
            for (int i = j; i <= n; i++) {
                int k = st[j - 1].find(get(1, i));
                //debug(i, j, k);
                if (dp[k][j - 1] <= get(k + 1, i)) {
                    dp[i][j] = get(k + 1, i);
                }
            }
        }
        st[j].init(n, j);
    }

    /*for (int i = 1; i <= n; i++){
        for (int j = 1; j <= n; j++){
            cout << dp[i][j] << ' ';
        }
        cout << endl;
    }*/

    int ans = 0;
    for (int i = 1; i <= n; i++){
        if (dp[n][i] != LLINF) ans = i;
    }

    cout << ans;

}

int main() {
    startTime = clock();
    ios_base::sync_with_stdio(false);

    bool llololcal = false;
#ifdef dddxxz
    freopen("input.txt", "r", stdin);
    freopen("output.txt", "w", stdout);
    llololcal = true;
#endif

    int TC = 1;
    //cin >> TC;

    for (int test = 1; test <= TC; test++) {
        debug(test);
        solve(test);
    }

    if (llololcal) cerr << endl << "Time: " << getCurrentTime() * 1000 << " ms" << endl;

    return 0;
}

Compilation message (stderr)

segments.cpp: In function 'int main()':
segments.cpp:18:20: warning: statement has no effect [-Wunused-value]
   18 | #define debug(...) 42
      |                    ^~
segments.cpp:146:9: note: in expansion of macro 'debug'
  146 |         debug(test);
      |         ^~~~~

• Subtask 1: 13 / 13
• Subtask 2: 14 / 14
• Subtask 3: 0 / 10
• Subtask 4: 0 / 36
• Subtask 5: 0 / 27