Submission #982026

#	Time	Username	Problem	Language	Result	Execution time	Memory
982026		vjudge1	Split the sequence (APIO14_sequence)	C++17	0 / 100	2 ms	348 KiB

sequence

#include <bits/stdc++.h>
using namespace std;
#define endl "\n"
#define int long long int
#define NUMMAX 200050
const int mod = 1e9 + 7;

int n, k;
int brr[201][100001];
int prefarr[100001], dp[2][100001], q[100001], l = 1, r = 1;

bool func1(int x, int y, int i) {
	return (dp[0][y] - dp[0][x] >= (prefarr[y] - prefarr[x]) * (prefarr[n] - prefarr[i]));
}

bool func2(int x, int y, int i) {
	return ((dp[0][y] - dp[0][x]) * (prefarr[i] - prefarr[y]) <=
	        (dp[0][i] - dp[0][y]) * (prefarr[y] - prefarr[x]));
}

void solve()
{
    cin >> n >> k;
    for (int i = 1; i <= n; i++){
        int x;cin >> x;
        prefarr[i] = prefarr[i - 1] + x;
    }


    for (int i = 1; i < k+1; i++){
		q[r++] = 0;
        
        for (int j = 1; j < n+1; j++){

			while (r - l > 1 && func1(q[l], q[l + 1], j)) l++;

			int x = q[l];
			dp[1][j] = dp[0][x] + (prefarr[j] - prefarr[x]) * (prefarr[n] - prefarr[j]);
			brr[i][j] = x;

			while (r - l > 1 && func2(q[r - 2], q[r - 1], j)) r--;
			q[r++] = j;
		}

		l = r = 1;
        
        for (int j = 1; j < n+1; j++){
            dp[0][j] = dp[1][j];
        }
	}

    int ans = -1, res = -1;
    for (int i = 1; i < n+1; i++){
		if (dp[0][i] > ans) ans = dp[0][i], res = i;
	}

	cout << ans << '\n';
    
    for (int i = 0; i < k; i++){
		cout << res << ' ';
		res = brr[k - i][res];
	}
}

signed main()
{
    freopen("sequence.in","r", stdin);
    freopen("sequence.out","w", stdout);


    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    cout.tie(0);

    int t = 1;
    // cin >> t;

    while (t--)
        solve();
}

Compilation message (stderr)

sequence.cpp: In function 'int main()':
sequence.cpp:67:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   67 |     freopen("sequence.in","r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~
sequence.cpp:68:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)' declared with attribute 'warn_unused_result' [-Wunused-result]
   68 |     freopen("sequence.out","w", stdout);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~~~~

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