题解 | #小乐乐与字符串#

//不是连续的子串
//只要在字符串中找到几个字符能组合成子串就算是“子串”
#include<stdio.h>
int main() {
    char str[8000] = {0};
    int count = 0;
    scanf("%s", str);
    char* p = str;
    long long c = 0;
    long long ch = 0;
    long long chn = 0;
    while (*p) {
        if (*p == 'C')
            c++;
        else if (*p == 'H')
            ch += c;
        else if (*p == 'N')
            chn += ch;
        p++;
    }
    printf("%lld\n", chn);
    return 0;
}