详细的题解见这里. 图片转自上面的博客 假设我们已经推导出来x在处取得最小值,并且注意到这个点是位于两个整点之间的,所以从这两个整数往左右两边枚举b就能找到b+c的最小值. 其实只用往一边枚举就够了,由于对称性,我们不妨假设b ≤ c,那么只要让b从2a开始递减枚举即可. #include <iostream> using namespace std; long long a, i; ;)%(i-a))i--;cout<<(i*i+)/(i-a)<<endl;};} 代…
Use of Function Arctan Time Limit:10000MS Memory Limit:0KB 64bit IO Format:%lld & %llu Submit Status Description It's easy to know that arctan(1/2)+arctan(1/3)=arctan(1).The problem is,to some fixed number A,you have to write a program to c…
转载请注明出处,谢谢http://blog.csdn.net/ACM_cxlove?viewmode=contents by---cxlove 题意:求sigma (gcd (i , j)) 1 <= i < j <= n 和POJ 2480类似,如果枚举j,求的话,还是会TLE的... 考虑sigma(gcd (i , n)) = sigma (d * phi[n / d]) d | n. 做法同样是先预处理出phi,然后枚举gcd = d. O(n)预处理,O(1)查询 #i…
Problem Description AFA is a girl who like runing.Today,he download an app about runing .The app can record the trace of her runing.AFA will start runing in the park.There are many chairs in the park,and AFA will start his runing in a chair and end i…