Submission #367244

#	Time	Username	Problem	Language	Result	Execution time	Memory
367244		parsabahrami	Split the sequence (APIO14_sequence)	C++17	78 / 100	1939 ms	86208 KiB

sequence

// Call my Name and Save me from The Dark
#include <bits/stdc++.h>
 
using namespace std;

typedef long long int ll;
typedef pair<int, int> pii;
 
#define SZ(x)                       (int) x.size()
#define F                           first
#define S                           second

const int N = 1e5 + 10, K = 210;
ll PS[N], S[N], dp[2][N]; int opt[K][N], A[N], n, k;

inline ll get(int l, int r) {
    return S[r] - S[max(0, l - 1)] - (PS[r] - PS[max(0, l - 1)]) * PS[max(0, l - 1)];
}

void DC(int j, int l = 1, int r = n, int optl = 1, int optr = n) {
    if (r - l < 0) return;
    int mid = (l + r) >> 1;
    dp[j & 1][mid] = 1e18;
    for (int i = optl; i <= min(mid, optr); i++) {
        if (get(i, mid) + dp[1 - (j & 1)][i - 1] < dp[j & 1][mid]) {
            dp[j & 1][mid] = get(i, mid) + dp[1 - (j & 1)][i - 1], opt[j][mid] = i;
        }
    }
    if (~opt[j][mid]) DC(j, l, mid - 1, optl, opt[j][mid]);
    DC(j, mid + 1, r, max(1, opt[j][mid]), optr);
}

int main() {
    scanf("%d%d", &n, &k);
    for (int i = 1; i <= n; i++) scanf("%d", &A[i]), PS[i] = PS[i - 1] + A[i];
    for (int i = 1; i <= n; i++) {
        S[i] = S[i - 1] + 1ll * A[i] * PS[i - 1];
    }
    memset(opt, -1, sizeof opt);
    for (int i = 0; i <= n; i++) dp[1][i] = S[i];
    for (int i = 2; i <= k + 1; i++) {
        DC(i);
    }
    printf("%lld\n", S[n] - dp[1 - (k & 1)][n]);
    int id = n; vector<int> vec;
    for (int i = k + 1; i > 1; i--) {
        if (opt[i][id] == -1) { cout << to_string(k); break; }
        vec.push_back(id = opt[i][id] - 1);
    }
    reverse(vec.begin(), vec.end());
    for (int &i : vec) printf("%d ", i);
    printf("\n");
    return 0;
}

Compilation message (stderr)

sequence.cpp: In function 'int main()':
sequence.cpp:34:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   34 |     scanf("%d%d", &n, &k);
      |     ~~~~~^~~~~~~~~~~~~~~~
sequence.cpp:35:39: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   35 |     for (int i = 1; i <= n; i++) scanf("%d", &A[i]), PS[i] = PS[i - 1] + A[i];
      |                                  ~~~~~^~~~~~~~~~~~~

• Subtask 1: 0 / 11
• Subtask 2: 11 / 11
• Subtask 3: 0 / 11
• Subtask 4: 17 / 17
• Subtask 5: 21 / 21
• Subtask 6: 29 / 29