Submission #377852

#	Time	Username	Problem	Language	Result	Execution time	Memory
377852		blue	Gap (APIO16_gap)	C++17	100 / 100	76 ms	2852 KiB

gap

#include "gap.h"
#include <algorithm>
#include <cmath>
using namespace std;
 
long long findGap(int T, int N)
{
    long long res = 0;
 
    if(T == 1)
    {
        long long s, t;
        long long mn;
        long long mx;
 
        s = 0;
        t = 1000'000'000'000'000'000LL;
 
        if(N % 2 == 0)
        {
            MinMax(s, t, &mn, &mx);
            s = mn + 1;
            t = mx - 1;
            for(int i = 2; i <= N/2; i++)
            {
                MinMax(s, t, &mn, &mx);
                res = max(res, mn - (s-1));
                res = max(res, (t+1) - mx);
 
                s = mn + 1;
                t = mx - 1;
            }
            res = max(res, mx - mn);
        }
        else
        {
            MinMax(s, t, &mn, &mx);
            s = mn + 1;
            t = mx - 1;
            for(int i = 2; i <= (N+1)/2; i++)
            {
                MinMax(s, t, &mn, &mx);
                res = max(res, mn - (s-1));
                res = max(res, (t+1) - mx);
 
                s = mn + 1;
                t = mx - 1;
            }
        }
    }
    else if(T == 2)
    {
        long long s, t;
        long long mn, mx;
 
        s = 0;
        t = 1'000'000'000'000'000'000LL;
 
        MinMax(s, t, &mn, &mx); //M += N+1
 
        long long a1 = mn, aN = mx;
        long long gap = (aN-a1)/(N-1) + ((aN-a1) % (N-1) != 0);
 
        vector<long long> L, R;
L.push_back(a1);
R.push_back(a1);
for(long long x = a1+1; x < aN; x += gap)
{
    MinMax(x, std::min(x+gap-1, aN-1), &mn, &mx);
    if (mn != -1)
    {
        L.push_back(mn);
        R.push_back(mx);
    }
}
L.push_back(aN);
R.push_back(aN);

for(int i = 0; i < L.size()-1; i++)
{
    res = max(res, L[i+1] - R[i]);
}

    }
 
    return res;
}

Compilation message (stderr)

gap.cpp: In function 'long long int findGap(int, int)':
gap.cpp:79:18: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<long long int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   79 | for(int i = 0; i < L.size()-1; i++)
      |                ~~^~~~~~~~~~~~

• Subtask 1: 30 / 30
• Subtask 2: 70 / 70