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 solving mode, find the minimum spanning tree algorithm, etc.