ssd4 certification 1st variant

Roe格式 二维Euler fortran语言的，网格文件是非结构网格-This code computes a steady flow over a bump with the Roe flux by two solution methods: explicit 2-stage Runge-Kutta scheme and implicit (defect correction) method with the Jacobian exact for 1st-order scheme, on i

1st：快排序算法及优化(7.4-5)； 2nd：红黑树插入算法； 3rd：区间树上的重叠区间查找算法； 4th：求最近点对算法； 5th：最长公共子序列(LCS)算法； 6th：Huffman编码问题； -introduction to algorithms code