Runtime error on test 2

#include<iostream>
#include<algorithm>
#include<vector>
#include<unordered_map>
#include<array>
#include<functional>
#include<cstring>
#include<stack>
#include<queue>
#define endl '\n'
using namespace std;
using ll = long long;
template<typename T> using F = function<T>;
template<typename T> using V = vector<T>;
template<typename T, size_t size> using A = array<T, size>;
template<typename T1, typename T2 = T1> using P = pair<T1, T2>;
void _debug() {cerr << endl;}
template<typename T, typename... Args>
void _debug(const T& a, Args... b) {cerr << a << ' ', _debug(b...);}
#define debug(...) cerr<<'('<<#__VA_ARGS__<<"): ", _debug(__VA_ARGS__)
template<typename T>
ostream& operator<<(ostream& os, const V<T>& v) {
    for (const auto& i : v)
        os << i << ' ';
    return os;
}
template<typename T, size_t size>
ostream& operator<<(ostream& os, const A<T, size>& a) {
    for (auto i : a)
        os << i << ' ';
    return os;
}
constexpr int inf = 0x3f3f3f3f;
constexpr ll infll = (ll)inf << 32 | inf;
int table[256];
inline void init() {
    table['B'] = 0, table['G'] = 1, table['R'] = 2, table['Y'] = 3;
}
using block = A<P<int>, 4>;
istream& operator>>(istream& is, block& b) {
    char color, num;
    for (int i = 0; i < 4; i++)
        is >> color >> num, b[i] = {table[(int)color], num - '0'};
    return is;
}
int comp(int a, int b, int c, int d) {
    if (a > b) {swap(a, b);} if (b > c) {swap(b, c);} if (c > d) {swap(c, d);}
    if (a > b) {swap(a, b);} if (b > c) {swap(b, c);} if (a > b) {swap(a, b);}
    return a << 6 | b << 4 | c << 2 | d;
}
tuple<int, int, int, int> extr(int cond) {
    return {(cond >> 6) & 3, (cond >> 4) & 3, (cond >> 2) & 3, cond & 3};
}
int dp[2][256], s[2][256], stop[2];
bool ins[2][256];
inline void solve() {
    for (int k = 0; k < 2; k++)
        for (int i = 0; i < 256; i++)
            dp[k][i] = ~inf;
    int n, ans = ~inf; cin >> n;
    block curb; cin >> curb;
    int cond = comp(curb[0].first, curb[1].first, curb[2].first, curb[3].first);
    dp[0][cond] = 0, ins[0][cond] = true, s[0][stop[0]++] = cond;
    for (int k = 0; k + 1 < n; k++) {
        cin >> curb;
        int sum = 0;
        for (int i = 0; i < 4; i++)
            sum += curb[i].second;
        while (stop[k & 1]) {
            int cond = s[k & 1][--stop[k & 1]], cur = dp[k & 1][cond], a, b, c, d;
            tie(a, b, c, d) = extr(cond), ins[k & 1][cond] = false, dp[k & 1][cond] = ~inf;
            dp[~k & 1][cond] = max(dp[~k & 1][cond], cur - sum);
            if (!ins[~k & 1][cond])
                ins[~k & 1][s[~k & 1][stop[~k & 1]++] = cond] = true;
            for (int* e : {&a, &b, &c, &d})
                for (int i = 0; i < 4; i++) {
                    int x, y; tie(x, y) = curb[i];
                    if (x != *e) continue;
                    int tmp = *e; *e = curb[(i + 2) & 3].first;
                    switch (x) {
                    case 0: y = sum - y; break;
                    case 1: y = sum + y; break;
                    case 2: y = sum * y; break;
                    case 3: y = sum / y; break;
                    }
                    int next = comp(a, b, c, d);
                    dp[~k & 1][next] = max(dp[~k & 1][next], cur + y);
                    if (!ins[~k & 1][next])
                        ins[~k & 1][s[~k & 1][stop[~k & 1]++] = next] = true;
                    *e = tmp;
                }
        }
    }
    while (stop[~n & 1]) {
        int cond = s[~n & 1][--stop[~n & 1]];
        ans = max(ans, dp[~n & 1][cond]);
    }
    cout << ans << endl;
}
signed main() {
    // cin.tie(nullptr)->sync_with_stdio(false);
    int T = 1;
    cin >> T;
    init();
    while (T--)
        solve();
    return 0;
}