Benchmarking different methods to take input from stdin

This repository was made to measure the performance of these methods to take integer input from stdin in C++:

• std::cin
• std::cin with sync_with_stdio set to false
• scanf()
• fastscan() - takes characters using getchar() and converts it into an integer
• fastscan_unlocked() - takes character using getchar_unlocked() and converts it into an integer

Results

The results are available in the result directory and also given below.

Group	Experiment	Problem Space	Samples	Iterations	Failure	Baseline	us/Iteration	Iterations/sec	Min (us)	Mean (us)	Max (us)	Variance	Standard Deviation	Skewness	Kurtosis	Z Score
Input	cin	-9223372036854775808	30	10000	0	1	0.2602	3.8432e+06	2602	2687.6	2907	6323.9	79.523	1.14606	0.346018	1.07642
Input	cin_wo_sync	-9223372036854775808	30	10000	0	0.38432	0.1	1e+07	1000	1064.97	1265	3227.9	56.8146	2.64303	6.71072	1.14349
Input	scanf	-9223372036854775808	30	10000	0	0.37548	0.0977	1.02354e+07	977	1003.63	1056	387.413	19.6828	0.619739	0.242751	1.35313
Input	fastscan	-9223372036854775808	30	10000	0	0.13259	0.0345	2.89855e+07	345	352.967	367	29.6195	5.44238	0.364405	-0.238015	1.46382
Input	fastscan_unlocked	-9223372036854775808	30	10000	0	0.112606	0.0293	3.41297e+07	293	307.1	327	116.99	10.8162	0.00513204	-1.36834	1.3036

How to use

You can use the ./gen_result.sh to generate the results on your device.

Compiler and Device Specs

The specifications of the device on which these results were obtained are given below:

Component	Specification
Compiler	GNU 7.5.0
Processor	Intel(R) Core(TM) i5-9300H
RAM	8 GB

The data used to generate the benchmark is given in the resource directory.