记录编号	577860	评测结果	AAAAAAAAAAAAAAAA
题目名称	[USACO22 Open Gold]Pair Programming	最终得分	100
用户昵称	lihaoze	是否通过	通过
代码语言	C++	运行时间	0.333 s
提交时间	2022-11-25 18:24:35	内存使用	0.00 MiB

#include "bits/stdc++.h"

using i64 = long long;

constexpr int P = 1e9 + 7;
 
int norm(int x) {
    if (x < 0) 
        x += P;
    if (x >= P)
        x -= P;
    return x;
}
 
template <class T>
T power(T a, i64 b) {
    T res = 1;
    for (; b; b /= 2, a *= a)
        if (b % 2)
            res *= a;
    return res;
}
 
struct Z {
    int x;
    Z (int x = 0) : x(norm(x)) { }
    Z (i64 x) : x(norm(x % P)) { }
    int val() const {
        return x;
    }
    Z inv() const {
        assert(x != 0);
        return power(*this, P - 2);
    }
    Z & operator *= (const Z &rhs) {
        x = i64(x) * rhs.x % P;
        return *this;
    }
    Z & operator += (const Z &rhs) {
        x = norm(x + rhs.x);
        return *this;
    }
    Z & operator -= (const Z &rhs) {
        x = norm(x - rhs.x);
        return *this;
    }
    Z & operator /= (const Z &rhs) {
        return *this *= rhs.inv();
    }
    friend Z operator * (const Z &lhs, const Z &rhs) {
        Z res = lhs;
        res *= rhs;
        return res;
    }
    friend Z operator + (const Z &lhs, const Z &rhs) {
        Z res = lhs;
        res += rhs;
        return res;
    }
    friend Z operator - (const Z &lhs, const Z &rhs) {
        Z res = lhs;
        res -= rhs;
        return res;
    }
    friend Z operator / (const Z &lhs, const Z &rhs) {
        Z res = lhs;
        res /= rhs;
        return res;
    }
    friend std::istream & operator >> (std::istream &is, Z &a) {
        i64 v;
        is >> v;
        a = Z(v);
        return is;
    }
    friend std::ostream & operator << (std::ostream &os, const Z &a) {
        return os << a.val();
    }
};

void solve() {
    int n;
    std::cin >> n;

    std::string a, b;
    std::cin >> a >> b;
    a = " " + a, b = " " + b;

    std::vector<std::vector<Z>> f(n + 1, std::vector<Z>(n + 1));

    auto equal = [&] (int i, int j) {
        return std::isdigit(a[i]) == std::isdigit(b[j]) || a[i] == '1' || b[j] == '1';
    };

    for (int i = 0; i <= n; ++ i) {
        f[i][0] = f[0][i] = 1;
    }

    for (int i = 1; i <= n; ++ i) {
        for (int j = 1; j <= n; ++ j) {
            if (a[i] == '0' && b[j] == '0') {
                f[i][j] = 1;
            } else if (a[i] == '0') {
                f[i][j] = f[i][j - 1] + Z(b[j] == '+');
            } else if (b[j] == '0') {
                f[i][j] = f[i - 1][j] + Z(a[i] == '+');
            } else {
                f[i][j] = f[i - 1][j] + f[i][j - 1] - Z(equal(i, j)) * f[i - 1][j - 1];
            }
        }
    }

    std::cout << f[n][n] << '\n';
}

int main() {
    freopen("prob2_gold_22open.in", "r", stdin); 
    freopen("prob2_gold_22open.out", "w", stdout);
    
    int t;
    std::cin >> t;

    while (t --) {
        solve();
    }
    return 0;
}