Word Length and Frequency

#include<bits/stdc++.h>

using namespace std;

string s,s1;

int frequency[40];

int main()
{
    int len,i,a;

    stringstream ss;

    while(cin>>s)
    {
        while(1)
        {
            if(s=="#")
            {
                break;
            }

            len = s.length();

            if(s[len-1]=='-')
            {
                s.erase(len-1);
            }
            else
            {
                s+=" ";
            }

            for(i=0; i<len; i++)
            {
                a = s[i];

                if(a==39)
                {
                    continue;
                }
                if(s[i]=='-')
                {
                    continue;
                }
                if(s[i]>='A' && s[i]<='Z')
                {
                    s[i]+=32;
                }
                else if(s[i]<'a' || s[i]>'z')
                {
                    s[i] = ' ';
                }
            }

            ss<<s;

            cin>>s;
        }

        while(ss>>s1)
        {
            len = s1.length();

            int len1 = len;

            for(i=0; i<len; i++)
            {
                a = s1[i];

                if(a==39)
                {
                    len1--;
                }

                else if(s1[i]=='-')
                {
                    len1--;
                }
            }

            frequency[len1]++;
        }

        for(i=1; i<=31; i++)
        {
            if(frequency[i]>0)
            {
                printf("%d %d\n",i,frequency[i]);
            }
        }

        puts("");

        ss.clear();

        memset(frequency,0,sizeof(frequency));
    }

    return 0;
}