一.题目描述

Description

读入一篇英文文章，基于STL中的容器和算法（建议包含<map>、<algorithm>、<string>和<sstream>），删除所有标点符号，主要包括英文逗号“,”、句号“.”、分号“;”、感叹号“!”、问号“?”、双引号“"”和单引号“'”等，并将所有英文单词转化为小写，然后统计每个单词出现的频率并按“a-z”从小到大顺序输出结果。

二.输入与输出

Input

一段以exit为结束词的英文文本

Output

按从小到大顺序输出除标点外的小写单词及出现频率

Sample Input 1 

Saying Goodbye to Cambridge AgainVery quietly I take my leave
As quietly as I came here;
Quietly I wave goodbye
To the rosy clouds in the western sky.The golden willows by the riverside
Are young brides in the setting sun;
Their reflections on the shimmering waves
Always linger in the depth of my heart.The floating heart growing in the sludge
Sways leisurely under the water;
In the gentle waves of Cambridge
I would be a water plant!exit

Sample Output 1

a 1
again 1
always 1
are 1
as 2
be 1
brides 1
by 1
cambridge 2
came 1
clouds 1
depth 1
floating 1
gentle 1
golden 1
goodbye 2
growing 1
heart 2
here 1
i 4
in 5
leave 1
leisurely 1
linger 1
my 2
of 2
on 1
plant 1
quietly 3
reflections 1
riverside 1
rosy 1
saying 1
setting 1
shimmering 1
sky 1
sludge 1
sun 1
sways 1
take 1
the 11
their 1
to 2
under 1
very 1
water 2
wave 1
waves 2
western 1
willows 1
would 1
young 1

Sample Input 2 

Stray Birds"WHAT language is thine, O sea?"
"The language of eternal question."
"What language is thy answer, O sky?"
"The language of 'eternal' silence."exit

Sample Output 2

answer 1
birds 1
eternal 2
is 2
language 4
o 2
of 2
question 1
sea 1
silence 1
sky 1
stray 1
the 2
thine 1
thy 1
what 2

三.代码

#include <iostream>
#include <map>
#include <algorithm>
#include <string>
#include <sstream>using namespace std;bool isPunctuation(char c) {return c == ',' || c == '.' || c == ';' || c == '!' || c == '?' || c == '"' || c == '\'';
}string removePunctuation(const string& word) {string cleanedWord;for (size_t i = 0; i < word.size(); ++i) {char c = word[i];if (!isPunctuation(c)) {cleanedWord += c;}}return cleanedWord;
}int main() {string line, word;map<string, int> wordCount;while (getline(cin, line) && line != "exit") {transform(line.begin(), line.end(), line.begin(), ::tolower);stringstream ss(line);while (ss >> word) {string cleanedWord = removePunctuation(word);if (!cleanedWord.empty()) {wordCount[cleanedWord]++;}}}for (map<string, int>::iterator it = wordCount.begin(); it != wordCount.end(); ++it) {cout << it->first << " " << it->second << endl;}return 0;
}