A
#include <iostream>
using namespace std;
int cnt;
void solve(int n)
{
cnt=0;
while(n>=(1<<(cnt)))
{
cnt++;
}
}
int main()
{
int n;
cnt=0;
scanf("%d",&n);
solve(n);
printf("%d\n",cnt);
return 0;
}
B
#include <iostream>
#include <algorithm>
#define ll long long
using namespace std;
ll a[400005];
int main()
{
ll s;
int n;
scanf("%lld %lld",&n,&s);
for(int i=0;i<n;i++)
scanf("%lld",&a[i]);
ll ans=0;
int m=n/2;
sort(a,a+n);
if(a[m]==s);
else if(a[m]<s)
{
int i=m;
while(a[i]<s&&i<n)
{
ans+=s-a[i];
i++;
}
}else
{
int i=m;
while(a[i]>s&&i>=0)
{
ans+=a[i]-s;
i--;
}
}
printf("%lld\n",ans);
return 0;
}
C
#include <iostream>
#include <algorithm>
#include <string>
#define ll long long
using namespace std;
int main()
{
char a[1000005],b[1000005];
int n;
scanf("%d",&n);
getchar();
scanf("%s",a);
getchar();
scanf("%s",b);
int i=0,ans=0;
while(i<n)
{
if(a[i]!=b[i])
{
if((i+1)<n&&a[i+1]==b[i]&&a[i]==b[i+1])
{
ans+=1; i++;
}else ans++;
}
i++;
}
printf("%d\n",ans);
return 0;
}