Karti

#include <iostream>
using namespace std;
int main()
{
int i, j, n, k, l, count0=0, count1=0, cou=0, cou2=0;
cin >> n >> k;
int niza[n], tempNiza[n];
for(i=0; i<n; i++)
{
cin >> niza[i];
tempNiza[i] = niza[i];
}
for(i=0; i<n; i++)
{
if(tempNiza[i] == 0 and i+k<=n)
{
for(j=0, l=i; j<k; j++, l++)
{
if(tempNiza[l]==0)tempNiza[l] = 1;
else tempNiza[l] = 0;
}
count1++;
}
if(niza[i] == 1 and i+k<=n)
{
for(j=0, l=i; j<k; j++, l++)
{
if(niza[l]==1)niza[l] = 0;
else niza[l] = 1;
}
count0++;
}
}
for(i=n-1; i>n-k; i--)
if(niza[i]!=niza[i-1]) { cou++; break; }
for(i=n-1; i>n-k; i--)
if(tempNiza[i]!=tempNiza[i-1]) { cou2++; break; }
if(cou!=0 and cou2!=0) { cout << "-1"; return 0; }
if(count1<count0 and count1!=0 and cou2==0)cout << count1;
else if(count0!=0 and cou==0)cout << count0;
else cout << max(count0, count1);
return 0;
}