CodeForces - 955B（用char会超时。。。）

#include <bits/stdc++.h>
#define mem(a, b) memset(a, b, sizeof(a))
using namespace std;
const int maxn = , INF = 0x7fffffff;
string str;
int vis[];
int main()
{
    cin>> str;
    mem(vis, );
    int cnt = , ans = ;
    for(int i=; i<str.size(); i++)
            vis[str[i] - 'a']++;
    for(int i=; i<; i++)
        if(vis[i])
        {
            cnt++;
            if(vis[i] >= )
                ans++;
            if(cnt > )
            {
                cout<< "No" <<endl;
                return ;
            }
        }
    if(cnt == )
    {
        cout<< "No" <<endl;
    }
    else if(cnt == )
    {
        if(ans == )
            cout<< "Yes" <<endl;
        else
            cout<< "No" <<endl;
    }
    else if(cnt == )
    {
        if(ans)
            cout<< "Yes" <<endl;
        else
            cout<< "No" <<endl;
    }
    else if(cnt == )
        cout<< "Yes" <<endl;

    return ;
}