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More Fixes
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@ -840,16 +840,22 @@ tester.push_back(make_pair(5, 0));
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// sort is from the <algorithm> header
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sort(tester.begin(), tester.end(), [](const pair<int, int>& lhs, const pair<int, int>& rhs) {
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return lhs.second < rhs.second;
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});
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return lhs.second < rhs.second;
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});
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// Notice the syntax of the lambda expression,
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// [] in the lambda is used to "capture" variables.
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// For Example:
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// [] in the lambda is used to "capture" variables
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// The "Capture List" defines what from the outside of the lambda should be available inside the function body and how.
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// It can be either:
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// 1. a value : [x]
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// 2. a reference : [&x]
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// 3. any variable currently in scope by reference [&]
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// 4. same as 3, but by value [=]
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// Example:
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vector<int> dog_ids;
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// number_of_dogs = 3;
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for(int i = 0; i < 3; i++){
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for(int i = 0; i < 3; i++) {
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dog_ids.push_back(i);
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}
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@ -861,13 +867,10 @@ int weight[3] = {30, 50, 10};
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// Here's where lambda expressions come in handy
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sort(dog_ids.begin(), dog_ids.end(), [&weight](const int &lhs, const int &rhs) {
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return weight[lhs] < weight[rhs];
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});
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return weight[lhs] < weight[rhs];
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});
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// Note we captured "weight" by reference in the above example.
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// lambda are really useful for the case of structs
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// You can use lambda expressions instead of overloading
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// the "<" operator
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// More on Lambdas in C++ : http://stackoverflow.com/questions/7627098/what-is-a-lambda-expression-in-c11
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///////////////////////////////
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// Range For (C++11 and above)
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