7dnunS - Online C++0x Compiler & Debugging Tool

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

int main() {
	int n,k;
	string str;
	cin>>n>>k;
	cin>>str;
	int i = 0 , j = 0;
	multiset<char>ms;
	int maxi = 0;
	while(j<n){
		ms.insert(str[j]);
		char a = *ms.begin();
		char b = *ms.rbegin();
		while((b-a)>k){
			ms.erase(str[i]);
			i++;
			a = *ms.begin();
			b = *ms.rend();
		}
		maxi = max(maxi,(j-i+1));
		j++;
	}
	cout<<maxi<<endl;
	return 0;
}