就WA了#13一个点，拼劲全力无法战胜，讨论区里的hack全部通过，求调

#include <bits/stdc++.h>
using namespace std;
map<string, double> w;
string s;
double ans = 0.0;
void init() { w["H"] = 1, w["C"] = 12, w["N"] = 14, w["O"] = 16, w["F"] = 19, w["Na"] = 23, w["Mg"] = 24, w["Al"] = 27, w["Si"] = 28, w["P"] = 31, w["S"] = 32, w["Cl"] = 35.5, w["K"] = 39, w["Ca"] = 40, w["Mn"] = 55, w["Cu"] = 64, w["Zn"] = 65, w["Ag"] = 108, w["I"] = 127, w["Ba"] = 137, w["Hf"] = 178.5, w["Pt"] = 195, w["Au"] = 197, w["Hg"] = 201; }
int main()
{
    ios::sync_with_stdio(false);
    cin.tie(nullptr);
    init();
    cin >> s;
    string tmp = "";
    double num = 1, cnt = 0, ad, tot = 0;
    bool op = false;
    for (int i = 0; i < s.size(); i++)
    {
        char t = s[i];
        if (s[i - 1] == '~')
        {
            if (!tmp.empty())
                ans += num * w[tmp];
            if (isdigit(s[i]))
            {
                string tt = "";
                while (isdigit(s[i]))
                    tt.push_back(s[i++]);
                stringstream ss(tt);
                ad = 0, ss >> ad;
            }
            else
                ad = 1;
            cout << ans * 1.0 + ad * 18.0;
            return 0;
        }
        if (isupper(t))
        {
            if (!tmp.empty())
            {
                if (!op)
                    ans += num * w[tmp];
                else
                    cnt += num * w[tmp];
                num = 1, tmp.clear();
            }
            tmp.push_back(t);
        }
        if (islower(t))
            tmp.push_back(t);
        if (t == '_')
        {
            i += 2;
            string tt = "";
            while (s[i] != '}')
                tt.push_back(s[i++]);
            stringstream ss(tt);
            num = 0, ss >> num;
        }
        if (t == '(')
        {
            op = true;
            if (!tmp.empty())
                ans += w[tmp] * num, num = 1, tmp.clear();
        }
        if (t == ')')
        {
            op = false;
            if (!tmp.empty())
                cnt += num * w[tmp], num = 1, tmp.clear();
            if (s[i + 1] != '_')
                ans += cnt, cnt = 0;
            else
            {
                i += 3;
                string tt = "";
                while (s[i] != '}')
                    tt.push_back(s[i++]);
                stringstream ss(tt);
                num = 0, ss >> num;
                ans += cnt * num, num = 1, cnt = 0;
            }
        }
    }
    if (!tmp.empty())
        ans += w[tmp] * num;
    cout << ans;
    return 0;
}