题解 | #计算某字符出现次数#

#include <iostream>
#include <string>
#include <map>
#include <iterator>
using namespace std;

int main() {
    string s;
    char ch = 0;
    map<char, int> charCountMap;

    getline(cin, s);
    for (string::iterator it = s.begin(); it != s.end(); it++) {
        ch = *it;

        if (ch >= 'A' && ch <= 'Z') {
            ch = ch - 'A' + 'a';
        }

        charCountMap[ch]++;
    }

    ch = getchar();
    if (ch >= 'A' && ch <= 'Z') {
        ch = ch - 'A' + 'a';
    }
    cout << charCountMap[ch] << endl;

    return 0;
}
// 64 位输出请用 printf("%lld")