Beautiful Garden

题意：x轴上放了一些树，现在要移动一些树使得所有树都等间距，问最少要移动多少棵
思路：枚举，枚举第一棵树，和另一棵树，以及中间有多少树，这样就能知道等差数列的首项和公差，然后再循环一边计算出答案，保存最小值
代码：

#include 
   
     #include 
    
      #include 
     
       #include 
      
        using namespace std; #define INF 0x3f3f3f3f int t, n; double x[45]; const double eps = 1e-9; int solve() { if (n == 1) return 0; int ans = INF; for (int i = 0; i < n; i++) { for (int j = i + 1; j < n; j++) { for (int k = 1; k < n; k++) { int count = 0; double d = (x[j] - x[i]) / k; double a1 = x[i] - d; int jj = 0; for (int ii = 0; ii < n; ii++) { a1 += d; while (x[jj] < a1 && jj < n) jj++; if (jj == n) break; if (fabs(a1 - x[jj]) < eps) { count++; jj++; } } ans = min(ans, n - count); } } } return ans; } int main() { int cas = 0; scanf("%d", &t); while (t--) { scanf("%d", &n); for (int i = 0; i < n; i++) scanf("%lf", &x[i]); sort(x, x + n); printf("Case #%d: %d\n", ++cas, solve()); } return 0; }