请问一下大家为什么我的代码是零分呀？

#include <bits/stdc++.h>
using namespace std;
int n, last, cnt, dd[105];
string s;
bool a, b, c, d;
int main () {
	ios::sync_with_stdio(false);
	cin.tie(0), cout.tie(0);
	getline(cin, s);
	for (int i = 0; i < s.length(); i++)
		if (s[i] == ',') dd[++cnt] = i;
	for (int k = 1; k <= cnt; k++) {
		n = dd[k];
		for (int i = last; i <= n; i++) {
			if ('a' <= s[i] && s[i] <= 'z') a = 1;
			if ('A' <= s[i] && s[i] <= 'Z') b = 1;
			if ('0' <= s[i] && s[i] <= '9') c = 1;
			if (s[i] == '!' || s[i] == '@' || s[i] == '#' || s[i] == '$') d = 1;
		}
		if (a + b + c >= 2 && d && n - last >= 5 && n - last <= 11) {
			for (int i = last; i < n; i++) cout << s[i];
			cout << '\n';
		}
		last = n + 1, a = b = c = 0;
	}
	return 0;
}