UVa 10008 Whats Cryptanalysis

Code：

#include<stdio.h>

#include<stdlib.h>

#include<algorithm>

#include<iostream>

#include<cctype>

#include<map>

#include<vector>

using namespace std;

typedef pair<int,char> ii;

struct ff

{

    int num;

    char cha;

    ff(int n,char ch) : num(n),cha(ch) {}

    bool operator < (const ff &rhs) const

    {

        if(num>rhs.num) return true;

        if(num==rhs.num)

        {

            if(cha<rhs.cha) return true;

        }

        return false;

    }

};

int main()

{

    int cas;

    string line;

    map<char,int> ma;

    vector<ff> v;

    while(cin>>cas)

    {

        getline(cin,line);

        for(int cc=0; cc<cas; cc++)

        {

            string str;

            getline(cin,str);

            int len=str.length();

            for(int i=0; i<len; i++)

            {

                if(str[i]>='a'&&str[i]<='z'||str[i]>='A'&&str[i]<='Z')

                {

                    char ch=toupper(str[i]);

                    ma[ch]+=1;

                }

            }

        }

    }

    for(map<char,int>::iterator it=ma.begin(); it!=ma.end(); it++)

    {

        v.push_back(ff(it->second,it->first));

    }

    sort(v.begin(),v.end());

    int lenv=v.size();

    for(int i=0; i<lenv; i++)

    {

        printf("%c %d\n",v[i].cha,v[i].num);

    }

    return 0;

}