HJ10 题解 | #字符个数统计# bitmap思想

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

int countChar(string str, int len) {
    int temp = 0;
    int count[128];      //一个128的数组用值为1或0来标记字符是否出现过
    for (int i = 0; i < 128; i++) {
        count[i] = 0;
    }
    for (int i = 0; i < len; i++) {
        temp=str[i]-'\0';    //字符转数字
        if (temp>= 0 && temp <= 127) {
            count[temp] = 1;   //字符对应的位置标记为1；
        }
    }
    temp = 0;
    for (int i = 0; i < 128; i++) {   //统计1的个数即为字符种类
        temp += count[i];
    }

    return temp;
}
int main() {
    string str;
    getline(cin, str);
    int len = str.length();
    int charType = countChar(str, len);
    cout << charType;

    return 0;
}