2 2 10 10 20 20 3 1 1 2 2 1000 1000
1414.2 oh!
#include <cstdio>
#include <algorithm>
#include <cstring>
#include <cmath>
using namespace std;
int const INF = 0xffffff;
int const MAX = 6000;
int n, cnt;
double ans;
int fa[1002000], rank[1002000];
struct Node
{
int u, v, id;
}nd[105];
struct Edge
{
Node x, y;
double val;
}e[MAX];
bool cmp(Edge a, Edge b)
{
return a.val < b.val;
}
double dist(int x1, int y1, int x2, int y2)
{
return sqrt((x1 - x2) * (x1 - x2) + (y1 - y2) * (y1 - y2));
}
void UFset()
{
for(int i = 0; i < 1002000; i++)
fa[i] = i;
memset(rank, 0, sizeof(rank));
}
int Find(int x)
{
return x == fa[x] ? x : fa[x] = Find(fa[x]);
}
void Union(int a, int b)
{
int r1 = Find(a);
int r2 = Find(b);
if(r1 == r2)
return;
if(rank[r1] > rank[r2])
fa[r2] = r1;
else
{
fa[r1] = r2;
if(rank[r1] == rank[r2])
rank[r1]++;
}
}
bool Kruskal()
{
int u, v;
int num = 0;
UFset();
for(int i = 0; i < cnt; i++)
{
u = e[i].x.id;
v = e[i].y.id;
double tmp = dist(e[i].x.u, e[i].x.v, e[i].y.u, e[i].y.v);
if(tmp >= 10 && tmp <= 1000)
{
if(Find(u) != Find(v))
{
ans += (e[i].val * 100);
Union(u, v);
num++;
}
if(num == n - 1)
return true;
}
}
return false;
}
int main()
{
int T;
scanf("%d", &T);
while(T--)
{
int x, y;
cnt = 0;
ans = 0;
scanf("%d", &n);
for(int i = 0; i < n; i++)
{
scanf("%d %d", &nd[i].u, &nd[i].v);
nd[i].id = nd[i].u * 1000 + nd[i].v;
}
for(int i = 0; i < n; i++)
{
for(int j = i + 1; j < n; j++)
{
e[cnt].x.u = nd[i].u;
e[cnt].x.v = nd[i].v;
e[cnt].x.id = nd[i].id;
e[cnt].y.u = nd[j].u;
e[cnt].y.v = nd[j].v;
e[cnt].y.id = nd[j].id;
e[cnt++].val = dist(nd[i].u, nd[i].v, nd[j].u, nd[j].v);
}
}
sort(e, e + cnt, cmp);
if(!Kruskal())
printf("oh!\n");
else
printf("%.1f\n", ans);
}
}
HDU 1875 畅通工程再续 (Kruskal + hash)
原文:http://blog.csdn.net/tc_to_top/article/details/43669757