Submission #344905

#	Time	Username	Problem	Language	Result	Execution time	Memory
344905		spike1236	Split the sequence (APIO14_sequence)	C++14	100 / 100	1394 ms	81132 KiB

sequence

#include <bits/stdc++.h>
using namespace std;

const int MAXN = 1e5 + 1;
long long dp[2][MAXN];
long long pref[MAXN];
int opt[201][MAXN];

void calc(int k, int l, int r, int optl, int optr) {
    if(l > r) return;
    int m = l + r >> 1;
    long long res = 0;
    opt[k][m] = optl;
    for(int i = optl; i <= std::min(m - 1, optr); ++i) {
        long long cur = dp[(k & 1) ^ 1][i] + pref[i] * (pref[m] - pref[i]);
        if(cur > res) {
            res = cur;
            opt[k][m] = i;
        }
    }
    dp[k & 1][m] = res;
    calc(k, l, m - 1, optl, opt[k][m]);
    calc(k, m + 1, r, opt[k][m], optr);
}

int main() {
    int n, K;
    scanf("%d %d\n", &n, &K);
    for(int i = 1; i <= n; ++i) {
        int x;
        scanf("%d", &x);
        pref[i] = pref[i - 1] + x;
    }
    for(int i = 1; i <= K; ++i)
        calc(i, i + 1, n, i, n);
    printf("%lld\n", dp[K & 1][n]);
    int pos = n;
    for(int i = K; i > 0; --i)
        pos = opt[i][pos], printf("%d ", pos);
    return 0;
}
/**
7 3
4 1 3 4 0 2 3
*/

Compilation message (stderr)

sequence.cpp: In function 'void calc(int, int, int, int, int)':
sequence.cpp:11:15: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   11 |     int m = l + r >> 1;
      |             ~~^~~
sequence.cpp: In function 'int main()':
sequence.cpp:28:10: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   28 |     scanf("%d %d\n", &n, &K);
      |     ~~~~~^~~~~~~~~~~~~~~~~~~
sequence.cpp:31:14: warning: ignoring return value of 'int scanf(const char*, ...)', declared with attribute warn_unused_result [-Wunused-result]
   31 |         scanf("%d", &x);
      |         ~~~~~^~~~~~~~~~

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