C++ <统计单词数及单个字母出现次数>

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原创最新推荐文章于 2026-02-24 05:30:30 发布 2k 阅读 AI 写同款· GEO 优化 ›

C++统计给定文本中每个单词出现的次数并输出结果到文件思路：将给定文件按行读入–>去除每行中出现的非字母字符–>以空格分隔读入每个单词–>统计单词出现的次数。按行读入文件并保存到一个string中 string tmp, strFile; ifstream file("1.txt"); while (getline(file, tmp)) { strFile.append(tmp); tmp.clear(); }... 阅读详情

运行结果：

 Enter a string: For example, the input
 4 words
 1 a
 3 e
 1 f
 1 h
 1 i
 1 l
 1 m
 1 n
 1 o
 2 p
 1 r
 2 t
 1 u
 1 x

countWords.cpp

#include <iostream>
#include <string>
#include <cstring>

using namespace std;

int computeWords(const string& str);
void countOccurs(const string& str, int a[]);
void show(const string& str, const int a[], int LEN);

int main() {
    const int LETTER = 26;
    int a[LETTER] = {0};
    string str;

    cout << "Enter a string: ";
    getline(cin, str);

    int words = computeWords(str);
    countOccurs(str, a);

    cout << words << " words\n";
    show(str, a, LETTER);

    return 0;
}

int computeWords(const string& str) {
    int count = 0;
    for (int i = 0; i < str.length(); i++) {
        if (isalpha(str[i]) && (! isalpha(str[i +1])))
            count++;
    }

    return count;
}

void countOccurs(const string& str, int a[]) {
    for (int i = 0; i < str.length(); i++) {
        if (isupper(str[i]))
            a[str[i] - 'A']++;
        else if (islower(str[i]))
            a[str[i] - 'a']++;
    }
}

void show(const string& str, const int a[], int LEN) {
    char letters = 'a';
    for (int i = 0; i < LEN; i++) {
        if (a[i] != 0)
            cout << a[i] << ' ' << letters << "\n";
        letters++;
    }
}