题解 | #计算某字符出现次数#

#include <iostream>
using namespace std;

int main() {
    string str;
    char sign;
     getline(cin,str);
     cin>>sign;
     int res=0;
     int index='A'-'a';
     for(int i=0;i<str.size();i++)
     {
        if(str[i]>='0'&&str[i]<='9'&&str[i]==sign)
         res++;
         else if(str[i]>='a'&&str[i]<='z')
         {
            if(str[i]==sign||str[i]-32==sign)
            res++;
         }
         else if(str[i]>='A'&&str[i]<='Z')
         {
            if(str[i]==sign||str[i]+32==sign)
            res++;
         }
     }
     cout<<res<<endl;
    
}
// 64 位输出请用 printf("%lld")