Description
Harvard linguistics PRofessor George Kingsley Zipf (1902-1950) observed that the frequency of the kth most common Word in a text is roughly proportional to 1/k. He justified his observations in a book titled Human behavior and the principle of least effort published in 1949. While Zipf's rationale has largely been discredited, the principle still holds, and others have afforded it a more sound mathematical basis. You are to find all the words occurring n times in an English text. A word is a sequence of letters. Words are separated by non-letters. Capitalization should be ignored. A word can be of any length that an English word can be.Input
Input consists of several test cases. The first line of each case contains a single positive integer n. Several lines of text follow which will contain no more than 10000 words. The text for each case is terminated by a single line containing EndOfText. EndOfText does not appear elsewhere in the input and is not considered a word.Output
For each test case, output the words which occur n times in the input text, one word per line, lower case, in alphabetical order. If there are no such words in input, output the following line: There is no such word. Leave a blank line between cases.Sample Input
2In practice, the difference between theory and practice is alwaysgreater than the difference between theory and practice in theory. - AnonymousMan will occasionally stumble over the truth, but most of thetime he will pick himself up and continue on. - W. S. L. ChurchillEndOfTextSample Output
betweendifferenceinwill
#include<iostream>#include<sstream>#include<map>using namespace std;int main(){ string s; int n; map<string,int>m; while(cin>>n) { m.clear(); while(cin>>s&&s!="EndOfText") { for(int i=0;i<s.length();i++) { if(isalpha(s[i]))s[i]=tolower(s[i]); else s[i]=' '; } stringstream stream(s); while(stream>>s)m[s]++; } int flag=0; for(map<string,int>::iterator it=m.begin();it!=m.end();it++) { if(it->second==n){ cout<<it->first<<endl; flag=1; } } if(flag==0)cout<<"There is no such word."<<endl; cout<<endl; } return 0;}
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