#define ATCODER #define _USE_MATH_DEFINES #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include using namespace std; using ll = long long; using ld = long double; using pll = pair; using pdd = pair; //template using pq = priority_queue, greater>; #define FOR(i, a, b) for(ll i=(a); i<(b);i++) #define REP(i, n) for(ll i=0; i<(n);i++) #define ROF(i, a, b) for(ll i=(b-1); i>=(a);i--) #define PER(i, n) for(ll i=n-1; i>=0;i--) #define REPREP(i,j,a,b) for(ll i=0;i > #define VV2(type,n,m,val) vector< vector > val;val.resize(n);for(ll i;i #define VEC(type,n,val) vector val;val.resize(n) #define VL vector #define VVL vector< vector > #define VP vector< pair > #define SZ size() #define all(i) begin(i),end(i) #define SORT(i) sort(all(i)) #define BITI(i) (1<>i) & 1) != 0) #define ALLBIT(n) (ll(1)<v?v:n #define MP(a,b) make_pair(a,b) #define DET2(x1,y1,x2,y2) (x1)*(y2)-(x2)*(y1) #define DET3(x1,y1,z1,x2,y2,z2,x3,y3,z3) (x1)*(y2)*(z3)+(x2)*(y3)*(z1)+(x3)*(y1)*(z2)-(z1)*(y2)*(x3)-(z2)*(y3)*(x1)-(z3)*(y1)*(x2) #define INC(a) for(auto& v:a)v++; #define DEC(a) for(auto& v:a)v--; #define SQU(x) (x)*(x) #define L0 ll(0) #ifdef ATCODER #include using namespace atcoder; //using mint = modint1000000007; using mint2 = modint998244353; #endif template vector read(size_t n) { vector ts(n); for (size_t i = 0; i < n; i++) cin >> ts[i]; return ts; } template void read_tuple_impl(TV&) {} template void read_tuple_impl(TV& ts) { get(ts).emplace_back(*(istream_iterator(cin))); read_tuple_impl(ts); } template decltype(auto) read_tuple(size_t n) { tuple...> ts; for (size_t i = 0; i < n; i++) read_tuple_impl(ts); return ts; } using val = ll; using func = ll; val op(val a, val b) { return a + b; } val e() { return 0; } val mp(func f, val a) { return a + f; } func comp(func f, func g) { return f + g; } func id() { return 0; } ll g; bool f(val a) { return a < g; } ll di[4] = { 1,0,-1,0 }; ll dj[4] = { 0,1,0,-1 }; ll si[4] = { 0,3,3,0 }; ll sj[4] = { 0,0,3,3 }; //ll di[4] = { -1,-1,1,1 }; //ll dj[4] = { -1,1,-1,1 }; //ll di8[8] = { 0,-1,-1,-1,0,1,1,1 }; //ll dj8[8] = { -1,-1,0,1,1,1,0,-1 }; void solve() { ll n; cin >> n; VL a = read(n); DEC(a); VL p(n, -2); REP(i, n) { if (a[i] != -2) p[a[i]] = i; } vector dp(n + 1, vector(n + 2)); dp[0][1] = 1; REP(i, n) { VL s(n + 3); FOR(i0, i, n) s[i0 + 1] = s[i0] + (a[i0] != -2); s[n + 2] = s[n] + 2; s[n + 1] = s[n] + 1; FOR(j, 1, n + 2) { if (p[i] != -2) { // 一番右に入れる if (p[i] == j) { dp[i + 1][j + 2] += dp[i][j]; } else if (p[i] == j - 1) { // 二番目の右に入れる dp[i + 1][j + 1] += dp[i][j]; } else if (p[i] < j - 1 ){ // それ以外に入れる dp[i + 1][j] += dp[i][j]; } } else { if (j < n && a[j] == -2) { // 一番右に入れる dp[i + 1][j + 2] += dp[i][j]; } if (j && j < n + 1 && a[j - 1] == -2) { // 二番目の右に入れる dp[i + 1][j + 1] += dp[i][j]; } // それ以外に入れる dp[i + 1][j] += dp[i][j] * max(j - 1 - i - s[j - 1], 0LL); } } } mint2 ans = dp.back().back(); cout << ans.val() << "\n"; return; } int main() { ll t = 1; cin >> t; while (t--) { solve(); } return 0; }