1644D-D-CrossColoring.cpp

// url:https://codeforces.com/contest/1644/problem/D
// time:2022-02-23 08:05:33
// name:D-CrossColoring

#include <bits/stdc++.h>

constexpr int P = 998244353;
using i64 = long long;
// assume -P <= x < 2P
int norm(int x) {
    if (x < 0) {
        x += P;
    }
    if (x >= P) {
        x -= P;
    }
    return x;
}
template<class T>
T power(T a, int 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)) {}
    int val() const {
        return x;
    }
    Z operator-() const {
        return Z(norm(P - 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;
    }
};

void solve() {
    int n, m, k, q;
    std::cin >> n >> m >> k >> q;
    
    std::vector<int> x(q), y(q);
    for (int i = 0; i < q; i++) {
        std::cin >> x[i] >> y[i];
        x[i]--;
        y[i]--;
    }
    
    std::set<int> sx, sy;
    Z ans = 1;
    for (int i = q - 1; i >= 0; i--) {
        if ((sx.count(x[i]) && sy.count(y[i])) || int(sx.size()) == n || int(sy.size()) == m) {
            continue;
        }
        sx.insert(x[i]);
        sy.insert(y[i]);
        ans *= k;
    }
    
    std::cout << ans.val() << "\n";
}

int main() {
    std::ios::sync_with_stdio(false);
    std::cin.tie(nullptr);
    
    int t;
    std::cin >> t;
    
    while (t--) {
        solve();
    }
    
    return 0;
}