Loading... # Introduction It is a python script for analyzing performance of a C++ program, including time and memory cost. It is useful for Data Structure and Algorithm course. You need to provide: ``` data.cpp - the program to generate data for testing std.cpp - the standard program that outputs the right answer main.cpp - the program to test ``` # Implementation It is gnu-time that provides the main functions, i.e. measuring the time and memory cost. Follow the [document](https://www.gnu.org/software/time/) carefully to install it. The common issue is that you should use the real gnu-time, rather than "time" provided by the shell, which is mentioned in the doc. By the way, use `--help` option to learn how to use it. For macOS users like me, follow this for installation: [https://formulae.brew.sh/formula/gnu-time](https://formulae.brew.sh/formula/gnu-time) . Note that the `-f` (or`--format`) option is useful to get outputs we like. Having gnu-time, we can write the python script below to test the program with increasing data. Use `os.popen` to get the outputs of gnu-time, and then print the results in whatever formats. For example, a table-like format is convenient for further processing the results with Excel, like plotting. Read the codes to know how to use it. :) ```python import sys import os def check_ans(output_file1, output_file2): with open(output_file1) as f: output1 = f.read() with open(output_file2) as f: output2 = f.read() return output1 == output2 if __name__ == '__main__': os.system('g++ data.cpp -O3 -std=c++14 -o data') os.system('g++ std.cpp -O2 -std=c++14 -o std') os.system('g++ main.cpp -O2 -std=c++14 -o main') input_data = 'input.txt' ans_txt = 'ans.txt' output_txt = 'output.txt' scale = 10000 step = 10000 loop = 10 if len(sys.argv) >= 2: scale = int(sys.argv[1]) if len(sys.argv) >= 3: step = int(sys.argv[2]) if len(sys.argv) >= 4: loop = int(sys.argv[3]) print('\tscale\t\tProg Time(s)\tProg Mem(KB)\tStd Time(s)\tStd Mem(KB)') for i in range(0, loop): os.system('./data {} > {}'.format(scale, input_data)) print('\t' + str(scale) + '\t\t', end='') prog_info = os.popen( '(gtime -f"%e\t\t%M\t\t" ./main < {} > {}) 2>&1'.format(input_data, output_txt) ).readlines() print(prog_info[0][:-1], end='') std_info = os.popen( '(gtime -f"%e\t\t%M\t\t" ./std < {} > {}) 2>&1'.format(input_data, ans_txt) ).readlines() print(std_info[0][:-1], end='\n') not_same = os.system('diff -q {} {}'.format(ans_txt, output_txt)) if not_same: print('WA!') break else: scale += step ``` Then we can get things like: ```shell $ python tester.py 100000 100000 30 scale Prog Time(s) Prog Mem(KB) Std Time(s) Std Mem(KB) 100000 0.04 1952 0.04 2412 200000 0.09 2664 0.09 4144 300000 0.14 3616 0.15 5040 400000 0.22 5176 0.21 7304 500000 0.27 5724 0.26 8260 600000 0.29 7152 0.32 9976 700000 0.35 9408 0.38 12104 800000 0.42 10636 0.44 13028 900000 0.46 9704 0.52 14436 1000000 0.54 12020 0.60 17308 ``` Last modification：November 26th, 2020 at 09:04 am © 允许规范转载 Support 如果觉得我的文章对你有用，请随意赞赏 Appreciate the author