How to format outputs with cout in C++? You need IO Manipulators <iomanip>: Header providing parametric manipulators. There are also good tutorials on the Web: Output Formatting: http://arachnoid.com/cpptutor/student3.html Formatting Cout Output in C++ using iomanip: http://www.cprogramming.com/tutorial/iomanip.html
Tag: C
g++: sorry, unimplemented: non-trivial designated initializers not supported
Posted ong++ (version g++ (GCC) 4.8.1 20130603 (Red Hat 4.8.1-1)) report: $ g++ -std=c++11 solution.cpp -o sol solution.cpp: In function ‘int main()’: solution.cpp:50:57: sorry, unimplemented: non-trivial designated initializers not supported Stat init_stat {.depth = 0, .moves = tv, .vec = init}; ^ solution.cpp:50:57: sorry, unimplemented: non-trivial designated initializers not supported solution.cpp:50:57: sorry, unimplemented: non-trivial designated initializers
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How to get a 10-byte length random string in bash
Posted onHow to get a 10-byte length random string in bash. Use this script to get a 10-byte string of letters: tr -dc “[:alpha:]” < /dev/urandom | head -c 10 You can also get a string of letters or numbers: tr -dc “[:alnum:]” < /dev/urandom | head -c 10 Or printable characters except space: tr -dc
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Trap Ctrl-C in a Bash script
Posted onHow to trap Ctrl-C in a Bash script? The piece of code: # trap ctrl-c and call ctrl_c() trap ctrl_c INT function ctrl_c() { echo echo “Ctrl-C by user” # do the jobs exit }
Is cin much slower than scanf in C++?
Posted onI frequently hear that cin is significantly slower than scanf in C++. Is this true? And how to improve the efficiency of cin? It is really nice to use most of time. One discussion about that cin is very slow is here: http://apps.topcoder.com/forums/?module=Thread&threadID=508058&start=0&mc=7 In short: cin is not always slower (can be faster actually, see
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How to call C functions from OCaml code
Posted onI am writing a OCaml program but want to call some C functions provided in some source code or library. How to achieve this? Is there any good tutorials on this? A very good tutorial that is easy to follow and understand: How to wrap C functions to OCaml. A comprehensive reference manual: Chapter 19
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Consistency models for distributed systems
Posted onWhich are the consistency models used for distributed systems? Papers that survey the consistency models Robert C. Steinke and Gary J. Nutt. 2004. A unified theory of shared memory consistency. J. ACM 51, 5 (September 2004), 800-849. DOI=10.1145/1017460.1017464 http://doi.acm.org/10.1145/1017460.1017464 David Mosberger. 1993. Memory consistency models. SIGOPS Oper. Syst. Rev. 27, 1 (January 1993), 18-26. DOI=10.1145/160551.160553
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Statically linking C and C++ programs
Posted onHow to statically compile C and C++ projects? The compiled executable should lead no dynamical library during execution. I use gcc/g++ to compile the projects. Check this post: Statically Linking C and C++ Programs on Linux with gcc.
Single sign-in for social accounts for question2answer?
Posted onHow to enable single sign-in for social accounts for question2answer? These servers are required: Google, Facebook, Twitter, OpenID. This site moved from Loginza to Question2Answer Open Login which works like a charm. I use the Loginza and it works very well. For Q2A, SLonoed wrote a nice plugin for loginza. How to use it: Download
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Auto completion in Vim
Posted onHow to enable auto code completion in Vim, like in the IDE? Several plugins I use: snipMate: Plugin for using TextMate-style snippets in Vim omnicppcomplete: Plugin for C/C++ omnicompletion neocomplcache: Ultimate auto completion system for Vim
3 Ways of Making Case Insensitive Search in Vim/Vi
Posted onBy default, Vim/Vi’s search is case sensitive. However, if I want to search case insensitively, is there any method? For example, I search for dog, instead of matching dog only case sensitively, I also want to find out phases containing Dog, DOg, etc. There are several methods: 1. Setting the search to be case insensitive
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x86-64 calling convention by gcc
Posted onWhat is the x86-64 calling convention by gcc? The calling convention of the System V AMD64 ABI is followed on GNU/Linux. The registers RDI, RSI, RDX, RCX, R8, and R9 are used for integer and memory address arguments and XMM0, XMM1, XMM2, XMM3, XMM4, XMM5, XMM6 and XMM7 are used for floating point arguments. For
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strcmp and strncmp implementation in glibc
Posted onWhat is the strcmp and strncmp implementation in glibc? strcmp implementation in glibc 2.16: string/strcmp.c /* Copyright (C) 1991, 1996, 1997, 2003 Free Software Foundation, Inc. This file is part of the GNU C Library. The GNU C Library is free software; you can redistribute it and/or modify it under the terms of the GNU
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Enabling Debugging with CMake for a C++ Project
Posted onWhen developing a C++ project, debugging is an essential part of the process, as it allows you to identify and fix issues in your code. If you’re using CMake to build your project, it’s crucial to know how to enable debug mode to take advantage of debugging tools like gdb. In this post, we’ll walk
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How to get the size of a file in C
Posted onHow to get a file’s size in C? If you have the file stream (FILE * f): fseek(f, 0, SEEK_END); // seek to end of file size = ftell(f); // get current file pointer fseek(f, 0, SEEK_SET); // seek back to beginning of file // proceed with allocating memory and reading the file Or, #include
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ANSI C Grammar and ANSI C Grammar Specification in YACC
Posted onANSI C is a standardized version of the C programming language that was introduced in 1989 by the American National Standards Institute (ANSI). The ANSI C standard defines the syntax and semantics of the C language, including its grammar. In this post, we will explore the ANSI C grammar in more detail. The ANSI C
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scanf is dangerous, but what is the reason?
Posted onWe all know scanf / fscanf / sscanf is dangerous. But why? what is the exact reason? I thought the ‘%s’ is a problem that causes buffer overflow and ‘fgets’ is a better solution. But is it the exact reason? I pased a discussion by AndreyT and his discussion helps me figure it out: Claiming
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Converting String to long Integer in C
Posted onConverting a string to a long in C is a common operation that can be useful in various programming tasks. In this post, we will explore how to use the strtol and strtoul C library functions to convert a string to a long in C. Using strtol and strtoul The strtol and strtoul functions are
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Vim: case insensitive search
Posted onBy default, Vim does case sensitive search. How to make case-insensitive search in Vim? By default, Vim does case sensitive search. :set ignorecase can set Vim to conduct case insensitive search. However, it also affects substitutions, which is not we want However, how to do a case insensitive search only when it is needed? Use
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How to disable automatic comment insertion in Vim
Posted onHow to disable automatic comment insertion in Vim? Add to ~/.vimrc: au FileType c,cpp setlocal comments-=:// comments+=f:// More: http://vim.wikia.com/wiki/Disable_automatic_comment_insertion