【BZOJ 1013】球形空间产生器sphere

1.​​题目链接​​。题目大意：给出一个n维球面上的n+1个点的坐标，求解这个球心的坐标。

#include<bits/stdc++.h>
#define esp 1e-6
using namespace std;
int n;
#pragma warning(disable:4996)
double f[100], a[100][100];
bool gauss()
{
  int now = 1, to; double t;
  for (int i = 1; i <= n; i++)
  {
    for (to = now; to <= n; to++)
      if (fabs(a[to][i]) > esp) break;
    if (to > n) continue;
    if (to != now)
      for (int j = 1; j <= n + 1; j++)
        swap(a[to][j], a[now][j]);
    t = a[now][i];
    for (int j = 1; j <= n + 1; j++) a[now][j] /= t;
    for (int j = 1; j <= n; j++)
      if (j != now)
      {
        t = a[j][i];
        for (int k = 1; k <= n + 1; k++)
          a[j][k] -= t * a[now][k];
      }
    now++;
  }
  for (int i = now; i <= n; i++)
    if (fabs(a[i][n + 1]) > esp) return 0;
  return 1;
}
int main()
{
  scanf("%d", &n);
  for (int i = 1; i <= n; i++)scanf("%lf", &f[i]);
  for (int i = 1; i <= n; i++)
  {
    for (int j = 1; j <= n; j++)
    {
      double tem;
      scanf("%lf", &tem);
      a[i][j] = 2 * (tem - f[j]);
      a[i][n + 1] += tem * tem - f[j] * f[j];
    }
  }
  gauss();
  for (int i = 1; i <= n - 1; i++)
  {
    printf("%.3lf ", a[i][n + 1]);
  }
  printf("%.3lf\n", a[n][n + 1]);
  return 0;
}