题解 | #字符个数统计#

#include <stdio.h>
#include <string.h>
int main() {
    char str[500], hash[127] = { NULL };
    int i, b, cnt = 0, k;
    scanf("%s", str);
    for (i = 0; i < strlen(str); i++) {
        k = str[i] % 17;
        k = k + str[i] / 17;
        while (hash[k] != NULL && hash[k] != str[i]) {
            k++;
        }//线性探测再散列
        if (hash[k] != str[i]) {
            hash[k] = str[i];
            cnt++;
        }
    }
    printf("%d", cnt);
    return 0;
}