Submission #333286

#	Time	Username	Problem	Language	Result	Execution time	Memory
333286		blue	Split the sequence (APIO14_sequence)	C++11	0 / 100	1109 ms	1260 KiB

sequence

#include <iostream>
#include <vector>
using namespace std;

int main()
{
    long long n, k;
    cin >> n >> k;

    long long a[n+1];
    a[0] = 0;
    for(long long i = 1; i <= n; i++)
    {
        cin >> a[i];
        a[i] += a[i-1];
    }

    vector<long long> split(k+2); //The i'th split occurs between split[i] and split[i+1]
    for(long long i = 0; i <= k; i++) split[i] = i;
    split[k+1] = n;

    bool flag = 0;
    long long x, y, m;
    long long segA, segB;
    for(int i = 1; i <= ((long long)(1e8))/k; i++)
    {
        flag = 1;
        for(long long i = k; i >= 1; i--)
        {
            segA = a[split[i]] - a[split[i-1]];
            segB = a[split[i+1]] - a[split[i]];

            if(segA == segB)
            {
                continue;
            }
            if(segA > segB)
            {
                if(segA - (a[split[i]] - a[split[i]-1]) < segB)
                {
                    continue;
                }
            }
            if(segB > segA)
            {
                if(segB - (a[split[i]+1] - a[split[i]]) < segA)
                {
                    continue;
                }
            }
            flag = 0;
            x = split[i-1] + 1;
            y = split[i+1] - 1;
            while(y - x > 1)
            {
                m = (x+y)/2;
                segA = a[m] - a[split[i-1]];
                segB = a[split[i+1]] - a[m];
                if(segA == segB)
                {
                    x = y = m;
                }
                else if(segA > segB)
                {
                    y = m;
                    if(segA - (a[m] - a[m-1]) < segB)
                        x = m;
                }
                else
                {
                    x = m;
                    if(segA > segB - (a[m+1] - a[m]))
                        y = m;
                }
            }
            if(x == y) split[i] = x;
            else split[i] = ((a[split[i+1]] - a[y] > a[x] - a[split[i]]) ? y : x);
        }
    }
    long long res = a[n] * a[n];
    for(long long i = 1; i <= k+1; i++) res -= (a[split[i]] - a[split[i-1]]) * (a[split[i]] - a[split[i-1]]);
    cout << res/2 << '\n';
    for(long long i = 1; i <= k; i++) cout << split[i] << ' ';
    cout << '\n';
}

Compilation message (stderr)

sequence.cpp: In function 'int main()':
sequence.cpp:22:10: warning: variable 'flag' set but not used [-Wunused-but-set-variable]
   22 |     bool flag = 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