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| #include<cstdio>
#include<algorithm>
using namespace std;
#define re register
#define int long long
const int MAXn = 5e3;
const int MAXm = 2e5;
template <class T>
inline void read(T &a) {
register char c;while (c = getchar(), c < '0' || c > '9');register T x(c - '0');while (c = getchar(), c >= '0' && c <= '9') {x = (x << 1) + (x << 3) + (c ^ 48);}a = x;
}
int n, m;
int fa[MAXn + 10];
int anc(int x) {
return fa[x] = fa[x] == x ? x : anc(fa[x]);
}
void Merge(int x, int y) {
if (anc(x) != anc(y)) {
fa[anc(x)] = y;
}
}
bool SameAnc(int x, int y) {
return anc(x) == anc(y);
}
void Init(int top) {
for (re int i = 1; i <= top; ++i) {
fa[i] = i;
}
}
struct Edge {
int u, v, w;
Edge():u(0), v(0), w(0){}
Edge(int u_, int v_, int w_):u(u_), v(v_), w(w_){}
inline bool operator<(Edge x) {
return this->w < x.w;
}
}edge[MAXm + 10];
int Kruskal() {
int ans = 0;
sort(edge + 1, edge + 1 + m);
Init(n);
for (re int i = 1; i <= m; ++i) {
if (!SameAnc(edge[i].u, edge[i].v)) {
ans += edge[i].w;
Merge(edge[i].u, edge[i].v);
}
}
return ans;
}
int ans;
signed main() {
read(n), read(m);
for (re int i = 1, u, v, w; i <= m; ++i) {
read(u), read(v), read(w);
edge[i] = Edge(u, v, w);
}
ans = Kruskal();
for (re int i = 1; i < n; ++i) {
if (!SameAnc(i, i + 1)) {
printf("orz\n");
return 0;
}
}
printf("%d\n", ans);
}
|
