如何计算单个字母的出现次数

Question

任务:编写一个程序,读取一行文本并输出每个字母的出现次数.

#include <iostream>
#include <string>
#include <cstring>
#define N 100
using namespace std;
int main()
{
    char alphabet[27] = "abcdefghijklmnopqrstuvwxyz";
    int alphacount[26];
    char lot[N], *p1;
    int txtlen, *p2;

    cout << " Enter a line of text: " << endl;
    cin.getline(lot, 99);

    txtlen = strlen(lot);

    p1 = lot;
    p2 = &txtlen;

    for (int x = 0; x < *p2; x++)
    {
        for (int y = 0; y < 26; y++)
        {
            if (*p1 == alphabet[y])
            {
                alphacount[y]++;
                p1++;
            }
        }
    }
    cout <<;
}

需要什么条件,用什么变量来输出字母的出现？例如:

> enter a line of text : mervlala

输出:

a - 2,
e - 1,
l - 2,
m - 1,
r - 1,
v - 1

Answer 1

你是在c ++上编程,你应该使用c ++方式.

#include <algorithm>

int main ()
{
    std::string textline;
    std::getline (std::cin,textline);

    for(char ch = 'a'; ch <= 'z'; ch++)
    {
        std::size_t n = std::count(textline.begin(), textline.end(), ch);
        if(n > 0)
            std::cout << " - " << n << "," << std::endl;
    }
}