oj.uz

Submission #332501

# Submission time Handle Problem Language Result Execution time Memory
332501 2020-12-02T18:08:52 Z alien_lover Hacker (BOI15_hac) C++14
0 / 100
 2 ms 364 KB 
#include <iostream>
#include <vector>
#include <algorithm>
#include <set>

using namespace std;

typedef long long ll;

#define all(x) begin(x), end(x)
#define sz(x) (int) x.size()

const int PRIME = 1e9 + 7;

int n;
vector<int> prefSum;

// i1 inclusive, i2 exclusive
int getCumSum(int i1, int i2){
    i1 %= n; i2 %= n;
    if(i1 > i2){
        return prefSum[n] - prefSum[i1] + prefSum[i2];
    }
    return prefSum[i2] - prefSum[i1];

    // use prefix sum vector
}


int main(){
    ios_base::sync_with_stdio(0); cin.tie(0);
    freopen("hacker.in", "r", stdin);
    // freopen("TASK_NAME.out", "w", stdout);
    // Use scanf printf

    cin >> n;
    
    vector<int> scores(n);
    prefSum.resize(n + 1);
    prefSum[0] = 0;
    int maxNumHacked = (n + 1) / 2;

    for(int i = 0; i < n; i++){
        cin >> scores[i];
        prefSum[i+1] = prefSum[i] + scores[i];
    }

    if(n == 2){
        cout << max(scores[0], scores[1]) << '\n';
        return 0;
    }

    multiset<int> sums;
    vector<int> minScores(n);

    for(int i = 0; i < 2 * n; i++){
        if(i >= maxNumHacked){
            sums.erase(sums.find(getCumSum(i - maxNumHacked, i)));
            // remove sum
        }
        sums.insert(getCumSum(i, i + maxNumHacked));
        // cout << sums.size() << '\n';
        minScores[i % n] = *sums.begin();
        // compare
    }

    int ans = INT32_MIN;
    for(int minScore: minScores){
        ans = max(ans, minScore);
    }
    cout << ans << '\n';


    

    // int maxScore = INT32_MIN;

    // for(int i = 0; i < n; i++){
    //     // cout << i + 1 << ' ' << i + 1 + splitLen << ' ' << getCumSum(i + 1, i + 1 + splitLen) << '\n';
    //     // cout << i + (n+1)/2 << ' ' << i + (n+1)/2 + splitLen << ' ' << getCumSum(i + (n+1)/2, i + (n+1)/2 + splitLen) << '\n';
    //     // cout << '\n';
    //     maxScore = max(maxScore, min(getCumSum(i + 1, i + 1 + splitLen), getCumSum(i + (n+1)/2, i + (n+1)/2 + splitLen)) + scores[i]);
    // }
    // // for(int el: prefSum){
    // //     cout << el << ' ';
    // // }
    
    // cout << maxScore << '\n';








    // int windowScore = 0;
    // for(int i = 0; i < maxNumHacked; i++){
    //     windowScore += scores[i];
    // }

    // int minDiff = windowScore * 2 - totSum;
    // int bestScore = windowScore;

    // for(int i = 0; i < n; i++){
    //     // compare window starting at i
    //     // subtract element at i, add next element
    //     if(abs(windowScore * 2 - totSum) < minDiff && windowScore > totSum - windowScore){
    //         minDiff = windowScore * 2 - totSum;
    //         bestScore = windowScore;
    //     }

    //     // maxScore = min(minDiff, windowScore);

    //     windowScore -= scores[i];
    //     windowScore += scores[(i + maxNumHacked) % n];

    // }
    // cout << bestScore << '\n';
}

Compilation message

hac.cpp: In function 'int main()':
hac.cpp:32:12: warning: ignoring return value of 'FILE* freopen(const char*, const char*, FILE*)', declared with attribute warn_unused_result [-Wunused-result]
   32 |     freopen("hacker.in", "r", stdin);
      |     ~~~~~~~^~~~~~~~~~~~~~~~~~~~~~~~~

Subtask #1
0 / 20.0

# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 364 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #2
0 / 20.0

# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 364 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #3
0 / 20.0

# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 364 KB Output isn't correct
2 Halted 0 ms 0 KB -

Subtask #4
0 / 40.0

# Verdict Execution time Memory Grader output
1 Incorrect 2 ms 364 KB Output isn't correct
2 Halted 0 ms 0 KB -