Submission #5646924

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Source Code Expand

#include <algorithm>
#include <cstdio>
#include <vector>
#include <set>
int fa[100005], arr[100005];
std::vector<int> vec[100005];
std::multiset<int> se;
int getfa(int u) { return u == fa[u] ? u : fa[u] = getfa(fa[u]); }
int main()
{
	// freopen("K.in", "r", stdin);
	int n, m;
	scanf("%d%d", &n, &m);
	if (m == n - 1)
	{
		puts("0");
		return 0;
	}
	for (int i = 0; i < n; i++)
	{
		scanf("%d", arr + i);
		se.insert(arr[i]);
		fa[i] = i;
	}
	for (int i = 0; i < m; i++)
	{
		int u, v;
		scanf("%d%d", &u, &v);
		fa[getfa(u)] = getfa(v);
	}
	for (int i = 0; i < n; i++)
		vec[getfa(i)].push_back(arr[i]);
	long long ans = 0;
	for (int i = 0; i < n; i++)
	{
		if (vec[i].empty())
			continue;
		int x = *std::min_element(vec[i].begin(), vec[i].end());
		ans += x;
		se.erase(se.find(x));
	}
	for (int i = 0; i < n - m - 2; i++)
	{
		if (se.empty())
		{
			puts("Impossible");
			return 0;
		}
		ans += *se.begin();
		se.erase(se.begin());
	}
	printf("%lld\n", ans);
	return 0;
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:13:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%d%d", &n, &m);
                       ^
./Main.cpp:21:23: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d", arr + i);
                       ^
./Main.cpp:28:24: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%d%d", &u, &v);
                        ^

Judge Result