Declaration
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vector<int> v; // Size of 100 and initialize all to 0 vector<int> v(100, 0) // Reserve size of 3, to prevent extra complexity for copying v.reserve(3); |
Simple operation
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int n; v.push_back(n); |
Fill with something
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fill(v.begin(), v.end(), 101); |
Combine two vectors…
Steps: Add root to queue If left child not null, add it to queue If…
Set variable Basic usage of SET
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SET(GCC_PATH /usr/bin/gcc) # SET variable "GCC_PATH" to "/usr/bin/gcc" |
To include existing variables in the SET…
Filenames should be all lowercase with underscores (_) or dashes (-) hello_world.cc All types like classes,…
Auto type
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// BEFORE for(vector<Person>::iterator it = personVec.begin(); it != personVec.end(); it++) {...} // IN C++ 11 for(auto it = personVec.begin(); it != personVec.end(); it++) {...} |
Auto type + Ranged-based for loop
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// BEFORE int i = 0; for(vector<Person>::iterator it = personVec.begin(); it != personVec.end(); it++, i++){ personVec[i].printName(); } // IN C++ 11 *Work only for container with begin() and end() // Read only access for(auto person : personVec){ person.printName(); } // To write for(auto& person : personVec){ person.name = "Overwritten"; } |
Initializer list
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// BEFORE personVec.push_back(person1); personVec.push_back(person2); personVec.push_back(person3); // IN C++ 11 personVec = { person1, person2, person3 } |
…
Trying to get input from the FILE* stream with image processing filter. Example One:…
Simple insert
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map<string, int> dataMap; // Two methods to insert // 1. Insert with pair dataMap.insert(pair<string, int>("TESTING", 1)); // 2. Insert with array dataMap["TESTING"] = 1; |
Access to second element using key (C++ 11)
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cout << dataMap.at("TESTING"); // Console output = 1 |
Iterate…
Language & platform: C++, Qt 5.7.0 Project setup + UML design + Wireframe + User…
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#include <unordered_map> using namespace std; unordered_map<int, int> map; map[2] = 4; // Map 4 to key value 2 auto p = map.find(3); //unordered_map<int, int>::const_iterator p = map.find(3); if (p != map.end()){ // Found } else{ // NOT Found } |
According to the documentation, the average searching complexity is O(1), by looking more into…