Codeforces Round #533 (Div. 2) B. Zuhair and Strings（字符串）

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

int main()
{
    int n,k;cin>>n>>k;
    string s;cin>>s;
    int ans[26]={0};
    for(int i=0;i<n;i++){
        int len=1;
        while(len<k&&s[i+1]==s[i]) ++len,++i;
        if(len==k) ++ans[s[i]-'a'];
    }
    cout<<*max_element(ans,ans+26);
    return 0;
}