求助，为啥不输出

#include <bits/stdc++.h>
using namespace std;
bool mima(string s){
    if (s.size() < 6 || s.size() > 12){
        return false;
    }
    int dxs = 0, tszf = 0;
    for (int i = 0; i <= s.size()-1; i++){
        if (!((s[i]>=97&&s[i]<=122)||(s[i]>=65&&s[i]<=90)||(s[i]>=48&&s[i]<=57)||(s[i]=='!')||(s[i]=='@')||(s[i]=='#')||(s[i]=='$'))){
            return false;
        }
        if (s[i]>=97&&s[i]<=122){
            dxs++;
        }
        if (s[i]>=65&&s[i]<=90){
            dxs++;
        }
        if (s[i]>=48&&s[i]<=57){
            dxs++;
        }
        if (s[i]=='!'){
            tszf++;
        }
        if (s[i]=='@'){
            tszf++;
        }
        if (s[i]=='#'){
            tszf++;
        }
        if (s[i]=='$'){
            tszf++;
        }
    }
    if (!(dxs>=2&&tszf>=1)){
        return false;
    }
    return true;
}
int main(){
    string a,b;
    cin >> a;
    int tmp = 0;
    for (int j = 0; j <= a.size()-1; j++){
        if (a[j] != ','){
            b[tmp] = a[j];
            tmp++;
            continue;
        }
        if (mima(b) == true){
            cout << b << endl;
            b = '\0';
            tmp = 0;
        }
    }
    return 0;
}