Envío 4102

Código

//
#include <bits/stdc++.h>
using namespace std;
#define INF 1000000000
#define MOD 1000000007
#define PI 3.14159265
#define EPS 1e-9
#define Pi acos(-1.0)
typedef pair<int, int> ii;
typedef long long ll;
typedef vector<ll> vll;
typedef pair<ll,ll> pll;
#define forr(i,a,b) for(int i=(a); i<(b); i++)
#define clean(arr,val) memset(arr,val,sizeof(arr))
#define forn(i,n) forr(i,0,n)
#define PB push_back
typedef vector<int> vi;
typedef vector<ii> vii;
typedef vector<pll> vpll;

/*CODE START HERE*/

int visited[30];
int ans, k, aS, pivot, different;
string s;

int main(){
    ios::sync_with_stdio(0);
    clean(visited,0);
    cin >> s;
    cin >> k;

    ans = 0;
    aS = 0;
    pivot = 0;
    different = 0;

    forn(i,(int)s.size()){
        //cout << "NOW ON " << s[i] << " AS " << aS << " PIVOT " << pivot << " DIFFERENT " << different << "\n";
        visited[s[i]-'a']++;
        if(visited[s[i]-'a'] == 1){
            different++;
        }

        if(different > k){
            for(int j = pivot; j < i; j++){
                aS--;
                visited[s[j]-'a']--;
                if(visited[s[j]-'a'] == 0){
                    different--;
                }

                if(different <= k){
                    pivot = j+1;
                    break;
                }
            }
        }

        aS++;
        ans = max(ans,aS);
    }
    cout << ans << "\n";
    return 0;
}