hdu 1875 畅通工程再续

一开始看到给的坐标直接懵了，也没想出来怎么处理。

枚举所有符合条件的长度，个数在n^2之内

然后人工加上一个序号就好了~

#include "iostream"
#include "algorithm"
#include "cstdio"
#include "cmath"
using namespace std;
#define MAXN 111

struct loc{
    double a,b;
}q[MAXN];

struct node{
    int x,y;
    double l;
    int n;
}p[MAXN*MAXN];

int fa[MAXN*MAXN];
int n, num;
double ans;
bool ok;
bool cmp(node x,node y)
{
    return x.l < y.l; 
}

void init()
{
    num = 0;
    ans = 0;
    for (int i = 0;i < MAXN*MAXN; ++ i)
        fa[i] = i,p[i].n = 1;
}

int find(int x) 
{
    return fa[x] = fa[x] == x ? x:find(fa[x]);
}

void process()
{
    init();
    cin >> n;
    for (int i = 0;i < n ; ++ i) 
        cin >> q[i].a >> q[i].b;
    for (int i = 0;i < n; ++ i)
        for (int j = i+1;j < n; ++ j) {
        p[num].x = i;
        p[num].y = j;
        double len =  sqrt((q[i].a - q[j].a)*(q[i].a - q[j].a) + (q[i].b - q[j].b)*(q[i].b- q[j].b));
        if (len >= 10 && len <= 1000) {
            p[num].l = len;
            num++;
            }
        }
        sort(p,p+num,cmp);
        for (int i = 0; i < num ; ++ i) {
            int x = find(p[i].x);
            int y = find(p[i].y);
            if (x != y) {
                fa[y] = x;
                ans += p[i].l*100;
                p[x].n += p[y].n;
            }
        }
        int max = -1;
        for (int i = 0;i < num; ++ i)
            if (p[i].n > max) max = p[i].n;
        if (max == n) printf("%.1lf
",ans);
        else cout << "oh!" << endl;
}

int main()
{
    int T;
    cin >> T;
    while (T--) {
        process();
    }
    return 0;
}