题解 | #计算某字符出现次数#

/*说一下思路吧：统计字符在某字符中出现的次数，用循环遍历的方法逐个进行对比；不区分大小写，就把他们统一用c/c++中的库函数tolower()进行处理为小写，注意添加上'cctype'这个头文件*/
#include <iostream>
#include<string>
#include <cctype>
using namespace std;

int main()
{
	string str;
	char ch;
	getline(cin, str);
	cin >> ch;
	int occurrenceCount = 0;
	int i = 0;
	char lowerch = tolower(ch);//将目标字符转换为小写
	for (i = 0; i < str.size(); i++)
	{
		if (lowerch == tolower(str[i]))//将字符串中的字符逐一转换为小写并与目标字符对比
		{
			occurrenceCount++;
		}
	}
	cout << occurrenceCount << endl;
	return 0;
}