最小生成树和次小生成树的裸题
#include <bits/stdc++.h>
using namespace std;
const int INF = 1000000000;
const int maxn = 100 + 10;
int T,n,m,ans,ans2,p[maxn],fa[maxn];
struct node {
int a, b, c;
bool operator < (const node& rhs) const {
return c < rhs.c;
}
}a[maxn*maxn];
vector<node> g;
int _find(int x, int p[]) { return p[x] == x ? x : p[x] = _find(p[x], p); }
void solve() {
sort(a, a+m);
int cnt = 1;
ans = 0;
g.clear();
for(int i=1;i<=n;i++) p[i] = i;
for(int i=0;i<m;i++) {
int x = _find(a[i].a, p), y = _find(a[i].b, p);
if(x != y) {
p[x] = y;
g.push_back(a[i]);
++cnt;
ans += a[i].c;
}
if(cnt == n) break;
}
ans2 = INF;
for(int i=0;i<g.size();i++) {
node v = g[i];
int cur = 0, cnt = 1;
for(int j=1;j<=n;j++) fa[j] = j;
for(int j=0;j<m;j++) {
if(v.a == a[j].a && v.b == a[j].b && v.c == a[j].c) continue;
int x = _find(a[j].a, fa), y = _find(a[j].b, fa);
if(x != y) {
fa[x] = y;
++cnt;
cur += a[j].c;
}
if(cnt == n) break;
}
if(cnt == n) ans2 = min(ans2, cur);
}
}
int main() {
scanf("%d",&T);
while(T--) {
scanf("%d%d",&n,&m);
for(int i=0;i<m;i++) scanf("%d%d%d",&a[i].a,&a[i].b,&a[i].c);
solve();
printf("%d %d\n",ans,ans2);
}
return 0;
}