Submission #538912

#	Time	Username	Problem	Language	Result	Execution time	Memory
538912		Monarchuwu	Triple Jump (JOI19_jumps)	C++17	19 / 100	451 ms	127448 KiB

jumps

#include<iostream>
#include<algorithm>
using namespace std;
typedef long long ll;

const int N = 5000 + 3;
int n, lg[N];
ll a[13][N];

int get(int l, int r) {
    int k = lg[r - l + 1];
    return max(a[k][l], a[k][r - (1 << k) + 1]);
}

ll dp[N][N];
int main() {
    cin.tie(NULL)->sync_with_stdio(false);
    cin >> n;
    for (int i = 1; i <= n; ++i) cin >> a[0][i];

    for (int j = 0; j < 12; ++j)
        for (int i = 1; i + (2 << j) - 1 <= n; ++i)
            a[j + 1][i] = max(a[j][i], a[j][i + (1 << j)]);

    lg[1] = 0;
    for (int i = 2; i <= n; ++i) lg[i] = lg[i >> 1] + 1;

    for (int i = 1; i <= n; ++i)
        for (int k = i + 2; k <= n; ++k)
            dp[i][k] = a[0][i] + get(i + 1, (i + k) >> 1) + a[0][k];

    for (int len = 3; len <= n; ++len)
        for (int i = 1, j = len; j <= n; ++i, ++j)
            dp[i][j] = max({ dp[i][j - 1], dp[i + 1][j], a[0][i] + get(i + 1,(i + j) >> 1) + a[0][j] });

    int q, l, r; cin >> q; while (q--) {
        cin >> l >> r;
        cout << dp[l][r] << '\n';
    }
}
/**  /\_/\
 *  (= ._.)
 *  / >0  \>1
**/

• Subtask 1: 5 / 5
• Subtask 2: 14 / 14
• Subtask 3: 0 / 27
• Subtask 4: 0 / 54