题解 | 字符个数统计

#include <stdio.h>

int main() {
    char str[501] = {0};
    char hashmap[128] = {0};
    int cnt = 0;
    int len = 0; 
    scanf("%[^\n]", str);
    len = strlen(str);

    for (int i = 0; i < len; i++) {
        hashmap[str[i]] = 1;
    }

    for (int j = 0; j < 128; j++) {
        cnt += hashmap[j];
    }
    printf("%d\r\n", cnt);
    return 0;
}