auto map<deque<string>, vector<string>> mymap; for(auto iter = mymap.begin(); iter!= mymap.end(); ++iter) {

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Corey Allison
5 years ago
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4 auto auto

5 auto How can we clean this up better? The auto keyword! map<deque<string>, vector<string>> mymap; for(auto iter = mymap.begin(); iter!= mymap.end(); ++iter) { } dosomething(*(iter).first, *(iter).second);

6 for for map<string, int> mymap; for(auto thing : mymap) { dosomething(thing.first, thing.second); } map<string, int> mymap; for(auto iter = mymap. begin(); iter!= mymap. end(); ++iter) { auto thing = *iter; dosomething(thing.first, thing.second); }

7 template <typename T> T min(t a, T b) { return (a < b)? a : b; }

8 int a = 3, b = 9; int c = min<int>(a, b); s I don t have a min<int> :( But I know how to make one! template <typename T> T min(t a, T b) { return (a < b)? a : b; } int min<int>(int a, int b) { return (a < b)? a : b; }

10 std::vector<int> v(10); auto mid = v.begin() + v.size()/2; std::deque<int> d(13); auto some_iter = d.begin() + 3;

11 std::vector<int> v(10); auto mid = v.begin() + v.size()/2; Sounds right! std::deque<int> d(13); auto some_iter = d.begin() + 3;

12 std::list std::list<int> mylist(10); auto some_iter = mylist.begin() + 3;

13 std::list std::list<int> mylist(10); auto some_iter = mylist.begin() + 3;

14 std::list std::list<int> mylist(10); auto some_iter = mylist.begin() + 3; What s going on here?

16 Input Output Forward Bidirectional Random Access

17 ==!= Input Output Forward Bidirectional Random Access

18 vector<int> v =... vector<int>::iterator itr = v.begin(); int val = *itr; Input Output Forward Bidirectional Random Access

19 vector<int> v =... vector<int>::iterator itr = v.begin(); *itr = 12; Input Output Forward Bidirectional Random Access

20 vector<int> v =... vector<int>::iterator itr = v.begin(); int val = *itr; int val2 = *itr; Input Output Forward Bidirectional Random Access

21 -- vector<int> v =... vector<int>::iterator itr = v.begin(); ++itr; int val = *itr; --itr; int val2 = *itr; Input Output Forward Bidirectional Random Access

22 + - vector<int> v =... vector<int>::iterator itr = v.begin(); int val = *itr; itr = itr + 3; int val2 = *itr; Input Output Forward Bidirectional Random Access

24 Algorithms Functors/Lambdas Iterators Adapters Allocators Containers

25 You are here! Algorithms Functors/Lambdas Iterators Adapters Allocators Containers

28 Basic Types

29 vector<int> map<string, int>

30 Containers Basic Types

31 vector> Can we perform operations on containers regardless of what the container is?

33 Iterators Containers Basic Types

35 Algorithms Iterators Containers Basic Types

37 .pro

38 std::copy std::copy vector<int> v {561, 1105, 1729, 2465}; vector<int> vcopy(v.size()); std::copy(v.begin(), v.end(), vcopy.begin());

39 std::copy v: vcopy:

40 std::copy v: vcopy:

41 std::copy v: vcopy:

42 std::copy v: vcopy:

43 std::copy v: vcopy:

44 std::copy vector<int> v {561, 1105, 1729, 2465}; vector<int> vcopy(v.size()); std::copy(v.begin(), v.end(), vcopy.begin());

45 std::copy vector<int> v {561, 1105, 1729, 2465}; vector<int> vcopy(v.size()); std::copy(v.begin(), v.end(), vcopy.begin());

46 std::copy vector<int> v {561, 1105, 1729, 2465}; vector<int> vcopy(2); std::copy(v.begin(), v.end(), vcopy.begin());

47 std::copy v: vcopy: 0 0

48 std::copy v: vcopy: 561 0

49 std::copy v: vcopy:

50 std::copy v: vcopy:

51 std::copy v: vcopy:

52 std::copy C++ has a solution!

54 This is where iterator adaptors come in.

55 * ++

56 std::ostream_iterator * ++ std::ostream_iterator std::ostream

57 std::ostream_iterator.pro

58 std::ostream_iterator std::ostream_iterator<int> itr(cout, ", ") *itr = 3; // prints 3 to console ++itr; *itr = 1729; // prints 1729 to console ++itr; *itr = 13; // prints 13 to console Output: 3, 1729, 13,

59 std::ostream_iterator

60 std::ostream_iterator

61 std::ostream_iterator

62 std::ostream_iterator std::vector<int> v{3, 1, 4, 1, 5}; std::copy(v.begin(), v.end(), std::ostream_iterator<int>(cout, ", "))

64 std::back_inserter

65 std::copy v: vcopy:

67 std::inserter std::back_inserter std::front_inserter). insert push_back push_front.

68 .pro

69 std::vector<int> v; // empty vec auto itr = std::back_inserter(v); *itr = 1729; // does v.push_back(1729) ++itr; *itr = 13; // does v.push_back(13) ++itr; *itr = 3; // does v.push_back(3) v look like this: {1729, 13, 3}

70 vector<int> v {561, 1105, 1729, 2465}; vector<int> vcopy(v.size()); std::copy(v.begin(), v.end(), vcopy.begin());

71 vector<int> v {561, 1105, 1729, 2465}; vector<int> vcopy(v.size()); std::copy(v.begin(), v.end(), vcopy.begin());

72 vector<int> v {561, 1105, 1729, 2465}; vector<int> vcopy; std::copy(v.begin(), v.end(), vcopy.begin());

73 vector<int> v {561, 1105, 1729, 2465}; vector<int> vcopy; Start with empty vector std::copy(v.begin(), v.end(), vcopy.begin());

74 vector<int> v {561, 1105, 1729, 2465}; vector<int> vcopy; std::copy(v.begin(), v.end(), vcopy.begin());

75 vector<int> v {561, 1105, 1729, 2465}; vector<int> vcopy; std::copy(v.begin(), v.end(), vcopy.begin());

76 vector<int> v {561, 1105, 1729, 2465}; vector<int> vcopy; std::copy(v.begin(), v.end(), std::back_inserter(vcopy));

77 std::copy v: vcopy:

78 std::copy v: vcopy: 561

79 std::copy v: vcopy:

80 std::copy v: vcopy:

81 std::copy v: vcopy:

Advanced Associative Containers. Ali Malik

Advanced Associative Containers Ali Malik malikali@stanford.edu Game Plan Recap Map Iterators Further Usage Multimap auto and Range Based for Recap Associative Containers Useful abstraction for associating