Submission #299300

#	Time	Username	Problem	Language	Result	Execution time	Memory
299300		AaronNaidu	Split the sequence (APIO14_sequence)	C++14	50 / 100	521 ms	17632 KiB

sequence

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

ll dp[2500][2500];
ll dpAns[2500][2500];
ll n, k;
ll nums[2000];
ll prefSum[2000];

void explore(int s, int regions) {
    if (regions == 0)
    {
        return;
    }
    ll split = dpAns[s][regions];
    //cout << "Exploring " << s << " " << f << " " << regions << "\n";
    //cout << "Answer is " << split << " " << reg << "\n";
    cout << split << " ";
    explore(split+1, regions - 1);
}

ll getDP(int s, int regions) {
    if (regions > n-s)
    {
        return -1000000000000;
    }
    if (regions == 0)
    {
        return 0;
    }
    if (dp[s][regions] >= 0)
    {
        return dp[s][regions];
    }
    ll cand = 0;
    for (int i = s; i <= n-regions; i++)
    {
        ll thisCand = (prefSum[i] - prefSum[s-1]) * (prefSum[n] - prefSum[i]);
        ll maxLittleCand = -1;
        ll thisLeftRegions = 0;
        ll thisLittleCand = getDP(i+1, regions-1);
        if (maxLittleCand < thisLittleCand)
        {
            maxLittleCand = max(maxLittleCand, thisLittleCand);
        }
        thisCand += maxLittleCand;
        if (thisCand >= cand)
        {
            cand = max(cand, thisCand);
            dpAns[s][regions] = i;
        }
    }
    dp[s][regions] = cand;
    return cand;
}

int main() {
    cin >> n >> k;
    cin >> nums[1];
    prefSum[1] = nums[1];
    prefSum[0] = 0;
    for (int i = 1; i < n; i++)
    {
        cin >> nums[i+1];
        prefSum[i+1] = prefSum[i] + nums[i+1];
    }
    for (int i = 0; i <= n; i++)
    {
        for (int k = 0; k <= n; k++)
        {
            dp[i][k] = -1;
        }
    }
    ll ans = getDP(1, k);
    cout << ans << "\n";
    //cout << "Exploring\n";
    explore(1, k);
    //cout << "\b\n";
}

Compilation message (stderr)

sequence.cpp: In function 'll getDP(int, int)':
sequence.cpp:41:12: warning: unused variable 'thisLeftRegions' [-Wunused-variable]
   41 |         ll thisLeftRegions = 0;
      |            ^~~~~~~~~~~~~~~

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