Submission #1105301

#	Time	Username	Problem	Language	Result	Execution time	Memory
1105301		ducanh1234	Split the sequence (APIO14_sequence)	C++17	0 / 100	2093 ms	1104 KiB

sequence

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

const int mxN = 1e5 + 6;

int a[mxN], pre[mxN];

auto sumSegment(int l, int r) { 
    return pre[r] - (l > 0 ? pre[l - 1] : 0); 
}

int getMidPos(int l, int r){
    auto findVal = (l > 0 ? sumSegment(0, l - 1) : 0) + sumSegment(l, r) / 2;
    if(findVal <= pre[l])
        return l;
    auto midPos = upper_bound(pre + l, pre + r + 1, findVal) - pre - 1;
    auto curDis = pre[midPos + 1] - pre[midPos];
    auto nextDis = midPos + 1 < r ? pre[midPos + 2] - pre[midPos - 1] : 1e9;
    return midPos + (curDis > nextDis);
} 
auto maxPointInSeg(int l, int r){
    int midPos = getMidPos(l, r);
    int64_t point = 1LL * sumSegment(l, midPos) * sumSegment(midPos + 1, r);
    assert(l != r);
    return point;
}

struct Segment{
    int l, r;
    Segment(int _l, int _r): l(_l), r(_r) {}

    bool operator < (const Segment& other) const{
        return maxPointInSeg(l, r) > maxPointInSeg(other.l, other.r); 
    } 
};

void solve() {
    int n, k; 
    cin >> n >> k;
    
    for(int i = 0; i < n; ++i){
        cin >> a[i];
        pre[i] = (i > 0 ? pre[i-1] : 0) + a[i];
    }
    
    set<Segment> val;
    vector<int> pos;
    val.insert(Segment(0, n - 1));

    int64_t ans = 0;
    for(int i = 1; i <= k; ++i){
        auto [l, r] = *val.begin();
        val.erase(val.begin());
        ans += maxPointInSeg(l, r);
        auto midPos = getMidPos(l, r);
        pos.push_back(midPos+1);
        if(midPos > l) val.insert(Segment(l, midPos));
        if(midPos + 1 < r) val.insert(Segment(midPos + 1, r));
    }
    cout << ans << "\n";
    for(auto& p : pos)
        cout << p << ' ';
}


int main() {
    ios_base::sync_with_stdio(false); cin.tie(NULL);
    solve();
    return 0;   
}

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