题解 | #字符个数统计#

#include <stdio.h>

int main() {
    int a, b;
    char chMap[128] = {0};
    char ch;
    int retCount = 0;
    while('\n' != (ch = getchar()))
    {
        if(0 == chMap[ch]){
            retCount++;
            chMap[ch] = 1;
        }
    }
    
    printf("%d",retCount);
    return 0;
}