Uva 11577 - Letter Frequency

  // Verdict :: Accepted

/// Header file begin
#include <iostream>
#include <cstdio>
#include <cstring>
#include <map>
#include <string>
#include <vector>
#include <cmath>
#include <cctype>
#include <sstream>
#include <set>
#include <list>
#include <stack>
#include<utility>
#include <queue>
#include <algorithm>
/// End
//..........
/// Macro
#define sf scanf
#define pf printf
#define sfint(a,b) scanf("%d %d",&a,&b)
#define sfl(a,b) scanf("%ld %ld",&a,&b)
#define sfll(a,b) scanf("%lld %lld",&a,&b)
#define sfd(a,b) scanf("%lf %lf",&a,&b)
#define sff(a,b) scanf("%f %f",&a,&b)
#define lp1(i,n) for(i=0;i<n;i++)
#define lp2(i,n) for(i=1;i<=n;i++)
#define mem(c,v) memset(c,v,sizeof(c))
#define cp(a) cout<<" "<<a<<" "<<endl
#define nl puts("")
#define sq(x) ((x)*(x))
#define all(x) x.begin(),x.end()
#define reall(x) x.rbegin(),x.rend()
#define sz size()
#define gc getchar()
#define pb push_back
/// End.........

/// Size
#define mx7 20000100
#define mx6 1500000
#define mx5 100005
#define mx4 1000100
#define inf 1<<30                                           //infinity value
#define eps 1e-9
#define mx (65540)
#define mod 1000000007
#define pi acos(-1.0)

/// Macros for Graph

#define white 0
#define gray 1
#define black -1
#define nil -2

using namespace std;
//..................................................................................................................
typedef long long LL;
typedef long L;
typedef unsigned long long ull;
typedef unsigned long ul;
typedef unsigned int ui;
typedef pair<int, int> pii;

map<int,int>mpii;
map<char,int>mpc;
map<string,int>mpsi;
map<bool,int>mpbi;

template<class T> T gcd(T a, T b ) {return b<=0?a:gcd(b,a%b);}
template<class T> T large(T a, T b ) {return a>b?a:b;}
template<class T> T small(T a, T b ) {return a<b?a:b;}
template<class T> T diffrnce(T a, T b) {return a-b<0?b-a:a-b;}


struct my
{
    int freq;
    char ch;
};

bool cmp(my a, my b)
{
    return a.freq > b.freq;
}

int main()
{
    int t;
    my ar[200+5];
    vector<char>vch;

    sf("%d\n",&t);

    while(t--)
    {
        string s;
        getline(cin,s);

        int len=s.size(),arlen=0;

        vch.clear();
        mpc.clear();

        for(int i=0;i<len;i++)
        {
            if(s[i]>='A' and s[i]<='Z')
            {
                s[i] = (char) (s[i]+32);
            }

            if(s[i]==' ')
            {
                continue;
            }

            else
            {
                mpc[s[i]]++;
                ar[arlen].freq=mpc[s[i]];
                ar[arlen++].ch=s[i];
            }
        }

        sort(ar,ar+arlen,cmp);

//        for(int i=0;i<arlen;i++)
//        {
//            pf("%c-%d ",ar[i].ch,ar[i].freq);
//        }

        int maxi=ar[0].freq;

        for(int i=0;i<arlen;i++)
        {
            if(maxi == ar[i].freq)
            {
                vch.push_back(ar[i].ch);
            }

            else
            {
                //vch.push_back(ar[i].ch);
                break;
            }
        }

        sort(all(vch));

        int vlen=vch.size();

        for(int i=0;i<vlen;i++)
        {
            pf("%c",vch[i]);
        }

        nl;
    }

    return 0;
}

/*

Computers account for only 5% of the country's commercial electricity consumption.

output : co 

Computers account for only.

output : o */