ACM常用算法，内容涵盖了如快速傅里叶变换，求排列组合数，判断图形是凸集还是凹集，求解模线性方程，求最小生成树等算法-ACM commonly used algorithms, covering, such as fast Fourier transform, find the number of permutations and combinations to determine the graph is convex or concave set of linear equations so