G 糖果

并查集
放上一篇写的比较好的博客：链接: https://blog.csdn.net/the_ZED/article/details/105126583.
注意 f i n d find find函数要进行路径压缩

#include
#include
#include
#include
#include
#include
#define BUFF ios::sync_with_stdio(false),cin.tie(0),cout.tie(0)
using namespace std;
const int MOD = 2333;
const int N = 1e6 + 5;
const int INF = 0x3f3f3f3f;
typedef long long ll;

ll a[N], pre[N];

//ll find(ll x) {
//	while (x != pre[x])
//		x = pre[x];
//	return x;
//}
ll find(ll x) {
	if (x != pre[x])
		pre[x] = find(pre[x]);
	return pre[x];
}

void work() {
	ll n, m;
	cin >> n >> m;
	for (ll i = 1; i <= n; i++) {
		cin >> a[i];
		pre[i] = i;
	}
	for (ll i = 1; i <= m; i++) {
		ll u, v;
		cin >> u >> v;
		ll fu = find(u);
		ll fv = find(v);
		pre[fu] = fv;
		a[fu] = a[fv] = max(a[fu], a[fv]);
	}
	ll ans = 0;
	for (ll i = 1; i <= n; i++)
		ans += a[find(i)];
	cout << ans << 'n';
}

int main() {
	BUFF;
	
		work();
	return 0;
}