Submission #2901999

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Source Code Expand

#include<bits/stdc++.h>
#define X first
#define Y second
using namespace std;
typedef long long ll;
typedef pair<ll,ll> pll;

const ll N = 100005;

ll n, m, k, cc, c[N], p[2*N], ans;

vector<pair<ll, pll> > e;
vector<ll> v;

ll Find (ll X) {
	if(p[X] == X) return X;
	return p[X] = Find(p[X]);
}

int main()
{
	scanf("%lld%lld%lld",&n,&m,&k);
	for(ll i=1;i<=n;i++) {
		scanf("%lld",&c[i]);
	}
	iota(p+1, p+1+n+k, 1);
	cc = k;
	for(ll i=1;i<=m;i++) {
		ll A, B, C;
		scanf("%lld%lld%lld",&A,&B,&C);
		if(!c[A]) c[A] = ++cc;
		if(!c[B]) c[B] = ++cc;
		e.push_back({C, {c[A], c[B]}});
	}
	sort(e.begin(), e.end());
	for(auto &T : e) {
		ll A = T.Y.X, B = T.Y.Y, C = T.X;
		A = Find(A);
		B = Find(B);
		if(A == B) continue;
		p[A] = B;
		v.push_back(C);
	}
	if(v.size() < k-1) {
		puts("-1");
		return 0;
	}
	for(ll i=0;i<k-1;i++) {
		ans += v[i];
	}
	printf("%lld\n",ans);
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:22:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
  scanf("%lld%lld%lld",&n,&m,&k);
                                ^
./Main.cpp:24:22: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%lld",&c[i]);
                      ^
./Main.cpp:30:33: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
   scanf("%lld%lld%lld",&A,&B,&C);
                                 ^

Judge Result