题解 | #字符统计#

代码如下：

#include <iostream>

using namespace std;
char ch;
int cnt[3];

int classify(char ch) {
  if (ch >= 'A' && ch <= 'Z' || ch >= 'a' && ch <= 'z') return 0;
  if (ch >= '0' && ch <= '9') return 1;
  return 2;
}

int main() {
  while ((ch = getchar()) != '?') 
    cnt[classify(ch)]++;
  cout << "Letters=" << cnt[0] << endl;
  cout << "Digits=" << cnt[1] << endl;
  cout << "Others=" << cnt[2] << endl;
  return 0;
}