mirror of
https://git.sb/baoshuo/OI-codes.git
synced 2024-12-25 16:11:58 +00:00
38 lines
622 B
C++
38 lines
622 B
C++
// R38821808
|
|
|
|
#include <bits/stdc++.h>
|
|
|
|
using namespace std;
|
|
|
|
struct node {
|
|
int x, y, z;
|
|
|
|
node() {
|
|
x = y = z = 0;
|
|
}
|
|
};
|
|
|
|
double ed(node a, node b) {
|
|
return sqrt(pow(a.x - b.x, 2) + pow(a.y - b.y, 2) + pow(a.z - b.z, 2));
|
|
}
|
|
|
|
bool cmp(node a, node b) {
|
|
return a.z <= b.z;
|
|
}
|
|
|
|
int main() {
|
|
int n;
|
|
node a[50005];
|
|
double ans = 0.000;
|
|
scanf("%d", &n);
|
|
for (int i = 0; i < n; i++) {
|
|
scanf("%d%d%d", &a[i].x, &a[i].y, &a[i].z);
|
|
}
|
|
sort(a, a + n, cmp);
|
|
for (int i = 1; i < n; i++) {
|
|
ans += ed(a[i - 1], a[i]);
|
|
}
|
|
printf("%.3lf", ans);
|
|
return 0;
|
|
}
|