Submission #1818584

---

Source Code Expand

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
using namespace std;

struct TEdge
{
    int u, v, w;
} a[100005];
int n, m, k, c[100005], dsu[200005];
long long ans = 0;

inline bool operator<(const TEdge &a, const TEdge &b)
{
    return a.w < b.w;
}

int trace(int u)
{
    return (dsu[u] < 0 ? u : dsu[u] = trace(dsu[u]));
}

bool unity(int u, int v)
{
    if ((u = trace(u)) == (v = trace(v)))
        return false;
    if (dsu[u] > dsu[v])
        swap(u, v);
    dsu[u] += dsu[v];
    dsu[v] = u;
    return true;
}

int main()
{
    memset(dsu, -1, sizeof(dsu));
    scanf("%d%d%d", &n, &m, &k);
    --k;
    for (int i = 1; i <= n; i++)
    {
        scanf("%d", c + i);
        if (c[i] == 0)
            c[i] = n + i;
    }
    for (int i = 1; i <= m; i++)
        scanf("%d%d%d", &a[i].u, &a[i].v, &a[i].w);
    sort(a + 1, a + m + 1);
    for (int i = 1; k && i <= m; i++)
        if (unity(c[a[i].u], c[a[i].v]))
        {
            ans += a[i].w;
            --k;
        }
    printf("%lld", k ? -1 : ans);
}

Submission Info

Compile Error

./Main.cpp: In function ‘int main()’:
./Main.cpp:38:32: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
     scanf("%d%d%d", &n, &m, &k);
                                ^
./Main.cpp:42:27: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d", c + i);
                           ^
./Main.cpp:47:51: warning: ignoring return value of ‘int scanf(const char*, ...)’, declared with attribute warn_unused_result [-Wunused-result]
         scanf("%d%d%d", &a[i].u, &a[i].v, &a[i].w);
                                                   ^

Judge Result