题解 | #计算某字符出现次数#

#include<iostream>
#include<string>
using namespace std;
int main()
{
	char s1,s2;
	string S;
	getline(cin,S);
	cin>>s1;
	if(s1>='a'&&s1<='z'){
		s2=s1-32;
	}
	else if(s1>='A'&&s1<='Z')
	{
		s2=s1+32;
	}
	else{
		s2=s1;
	}
	int sum=0;
	for(int i=0;i<S.length();i++)
	{
		if(S[i]==s1||S[i]==s2){
			sum++;
		}
	}
	cout<<sum;
	return 0;
}