如何纪录字符串中字母出现的字数

Question

比如 aabxdfdddda： 2  b：1d：5f ：1

Answer 1

#include<iostream>
using namespace std;

void main()
{
	char s[100], Letter;
	cout << "输入字符串：";
	cin >> s;

	int count[26] = { 0 }, i, s_i; // 统计26个字母出现的次数

	int n = strlen(s);   //计数器
	for (i = 0; i<n; i++)
	{
		s_i = s[i] - 'a';
		count[s_i]++; // 字符
	}
	
	for (i = 0; i<26; i++)
	{
		if (count[i] != 0) // 若该字母出现
		{
			Letter = 'a' + i;
			cout << Letter << " : " << count[i] << endl; // 输出
		}
	}
}

Answer 2

#include<iostream>

#include<string>

using namespace std;

int main()

{

    cout << "请输入字符串:" << endl;

    string s;

    getline(cin, s);

    int count = s.size();

    char letter[26] = { 'a','b','c','d','e','f','g','h','i','j','k','l','m','n','o','p','q','r','s','t','u','v','w','x','y','z' };

    for (int i = 0; i < 26; i++)

    {

            int num = 0;

            for (int j = 0; j < count; j++)

            {

                    if (s[j] == letter[i])

                    {

                                num++;

                    }

            }

            if (num > 0)

            {

                    cout << letter[i] << ":" << num << endl;

            }

            num = 0;

        }

        system("pause");

        return 0;

}