WEBVTT 00:00.150 --> 00:04.140 Hello again! In this video, we are going to look at min and max algorithms. 00:05.340 --> 00:10.830 The standard library provides quite a few algorithms for finding the largest or smallest elements, 00:10.830 --> 00:11.850 or sometimes both. 00:12.540 --> 00:19.410 There are various functions which can take two arguments, an initializer list in C++11, or the 00:19.410 --> 00:20.850 traditional iterator range. 00:21.780 --> 00:27.300 By default, these will use the less-than operator of the element, or the argument, to find out the 00:27.300 --> 00:28.380 largest or smallest. 00:28.770 --> 00:32.310 But we can provide our own comparison operator, as a predicate. 00:33.150 --> 00:37.620 And I think, probably, rather than having lots of very similar slides, the best way to demonstrate this 00:37.620 --> 00:38.580 is to have a program. 00:39.840 --> 00:42.930 So here it is. We start off with a couple of string variables. 00:43.920 --> 00:47.640 The less-than operator will do alphabetical comparisons. 00:48.060 --> 00:54.030 So "first_word" will be less than "word2". The basic functions 00:54.030 --> 00:56.310 are just max and min with two arguments. 00:56.640 --> 00:59.280 And these will return the largest or the smallest element. 01:01.850 --> 01:07.670 We can also provide a predicate, for example, if we want to use the size of the string and not the 01:08.030 --> 01:14.660 alphabetical order of the characters. We can pass an initialize the list, and this will return 01:14.660 --> 01:17.510 the largest or the smallest element in the list. 01:18.830 --> 01:23.090 So we would expect to get "words" for the max(), and "collection" for the min(). 01:25.950 --> 01:32.040 There is minmax(), which will return a pair of values. So this will find both the minimum and the maximum. 01:32.610 --> 01:35.610 You can either give it 2 arguments or an initializer list. 01:36.780 --> 01:43.930 The first member of the returned pair will be the smallest argument or element, and the second member 01:43.980 --> 01:44.880 will be the largest. 01:47.260 --> 01:50.200 min_element() and max_element() will take an iterator range. 01:50.620 --> 01:57.280 We are going to use this vector as a container, to provide the iterator range. Then we pass the iterator 01:57.280 --> 01:58.870 range to max_element(). 01:59.410 --> 02:02.760 And this will return an [iterator] to the largest element in here. 02:02.770 --> 02:04.600 So that will be the "words". 02:06.520 --> 02:09.290 And again, we can provide a predicate if we want to. 02:09.310 --> 02:14.350 So this will return an iterator to the shortest element in the iterator range, which will 02:14.350 --> 02:15.340 be the letter 'a'. 02:17.830 --> 02:22.780 And then finally, we have minimax_element(), which combines minmax() and these two functions. 02:23.350 --> 02:25.990 So this will take an iterator range, like these two do. 02:26.470 --> 02:29.620 And it will return a pair of iterators, like minmax() does. 02:30.430 --> 02:35.230 And then the first member of the pair will be an iterator to the smallest element, and the second member 02:35.230 --> 02:37.540 will be an iterator to the largest element. 02:39.070 --> 02:40.300 So let's see what we get. 02:43.120 --> 02:48.880 So "word2" is greater than "first_word", "first_word" has more characters than "word2", and we get the 02:48.880 --> 02:50.320 expected values from those. 02:52.380 --> 02:58.500 Okay, so you may not find all of these useful, but they are there. Probably the most useful is just the version 02:58.500 --> 03:03.840 which takes two arguments and then the initializer list as well, perhaps. 03:05.010 --> 03:06.780 Okay, so that is it for this video. 03:07.140 --> 03:08.010 I will see you next time. 03:08.250 --> 03:10.080 Until then, keep coding!