/* -*- coding: utf-8 -*- * * 2494.cc: No.2494 Sum within Components - yukicoder */ #include #include #include using namespace std; /* constant */ const int MAX_N = 200000; const int MOD = 998244353; /* typedef */ template struct MI { int v; MI(): v() {} MI(int _v): v(_v % MOD) {} MI(long long _v): v(_v % MOD) {} MI operator+(const MI m) const { return MI(v + m.v); } MI operator-(const MI m) const { return MI(v + MOD - m.v); } MI operator*(const MI m) const { return MI((long long)v * m.v); } MI &operator+=(const MI m) { return (*this = *this + m); } MI &operator-=(const MI m) { return (*this = *this - m); } MI &operator*=(const MI m) { return (*this = *this * m); } bool operator==(const MI m) const { return v == m.v; } bool operator!=(const MI m) const { return v != m.v; } MI pow(int n) const { // a^n % MOD MI pm = 1, a = *this; while (n > 0) { if (n & 1) pm *= a; a *= a; n >>= 1; } return pm; } MI inv() const { return pow(MOD - 2); } MI operator/(const MI m) const { return *this * m.inv(); } MI &operator/=(const MI m) { return (*this = *this / m); } }; typedef MI mi; struct UFT { vector links, ranks, sizes; UFT() {} void init(int n) { links.resize(n); for (int i = 0; i < n; i++) links[i] = i; ranks.assign(n, 1); sizes.assign(n, 1); } int root(int i) { int i0 = i; while (links[i0] != i0) i0 = links[i0]; return (links[i] = i0); } int rank(int i) { return ranks[root(i)]; } int size(int i) { return sizes[root(i)]; } bool same(int i, int j) { return root(i) == root(j); } int merge(int i0, int i1) { int r0 = root(i0), r1 = root(i1), mr; if (r0 == r1) return r0; if (ranks[r0] == ranks[r1]) { links[r1] = r0; sizes[r0] += sizes[r1]; ranks[r0]++; mr = r0; } else if (ranks[r0] > ranks[r1]) { links[r1] = r0; sizes[r0] += sizes[r1]; mr = r0; } else { links[r0] = r1; sizes[r1] += sizes[r0]; mr = r1; } return mr; } }; /* global variables */ mi as[MAX_N]; UFT uft; /* subroutines */ /* main */ int main() { int n, m; scanf("%d%d", &n, &m); for (int i = 0; i < n; i++) scanf("%d", &(as[i].v)); uft.init(n); for (int i = 0; i < m; i++) { int u, v; scanf("%d%d", &u, &v); u--, v--; if (! uft.same(u, v)) { mi sum = as[uft.root(u)] + as[uft.root(v)]; int r = uft.merge(u, v); as[r] = sum; } } mi p = 1; for (int u = 0; u < n; u++) p *= as[uft.root(u)]; printf("%d\n", p.v); return 0; }