cpp.md

C++ Usage

[Compile]

• Compfest7: g++ [source.cpp] -O2 -s -static -lm -std=c++11 -o [executable];

[Range Variable]

• int (2^32) = 32 bit / 4 bytes, 2 Billion -> 2.147.483.648
• long (2^64) = 64 bit /8 bytes - 9.223.372.036.854.775.807
• float -> precision 7

[std::String in C++ 11]

• http://www.cplusplus.com/reference/string/string/
• get length of char size / length
• max_size() string == 9223372036854775807
• find() return size_t (int position)
• mystring.find('c') -> return position index;
• mystring.substr(3,4); //return substring from index 3 and has length 4
• mystring.erase(2,1); // erase string from index 2, with 1 character

[STD Algorithm]

• std::transform(v.begin(), v.end(), v.begin(), function) -> will change each element based on function
• std::find(begin,end,elm_search) -> return iterator, check found or not by using (it != end)
• std::reverse(begin,end) -> reverse a container / string
• std::lower_bound(arr.begin(), arr.end(), x) -> search in sorted array (binary search)
• std::stoi(string) -> to convert string to integer, stod -> to double
• std::for_each(begin, end, function) -> iterate all element and process it in function
• std:max_element(begin, end) -> return iterator, *it for elemen, distance(begin, it) -> for position

[Vector C++]

• vector can be set initial value = vector v(10, 5); // size 10, initial value 5
• searching using find();

[Set C++]

• All Element are distinct (count() function return 0 / 1, available or not)
• maintains the order of the elements (automatically ordered)
• using unordered_set (more faster), not necessary to maintain order data.
• using multiset if you want multiple instances of an element. multiset.count(elm) -> can return > 1
• lower_bound(x) returns an iterator to the smallest element in the set whose value is at least “x”
• upper_bound(x) returns an iterator to the smallest element in the set whose value is larger than “x”

[Map C++]

• Key-value data structure
• Automatically Ordered by Key

[Array Primitive]

• Sort Example sort(array, array + 3); // 3 == size array
• Reset Array : memset(arr, 0, sizeof(arr));

[Bitset]

• bitset<10> s(string("0010011010")); // from right to left
• values of a bitset can be efficiently manipulated using bit operators, & (AND), | (OR), ^ (XOR)

[Pair & Tuple]

• pair<int, int>, pair only has 2 attribute, 'first' and 'second' just like map.
• TODO ADD TUPLE DOCUMENTATION