WEBVTT 00:02.030 --> 00:04.760 To find out the position of the selected value. 00:04.790 --> 00:07.070 We need to traverse the list elements. 00:07.070 --> 00:13.670 So once the selected value is matched with the value of the current position, the method just needs 00:13.670 --> 00:15.620 to return its current position index. 00:15.620 --> 00:23.480 So the implementation of the search operation here, we're going to develop our search operation here. 00:23.480 --> 00:31.490 So we are developed the insert, hit the insert tail and insert and get here. 00:31.490 --> 00:35.150 So now we're going to develop our search operation. 00:35.150 --> 00:36.920 So my name is Stephan. 00:37.160 --> 00:40.550 Welcome to another lecture of our Cplusplus course. 00:40.550 --> 00:42.680 And let's get started. 00:56.720 --> 01:00.720 Now we're going to develop our search operation. 01:00.740 --> 01:01.240 Oops. 01:01.370 --> 01:02.170 Not like this. 01:02.180 --> 01:02.810 Here. 01:03.080 --> 01:04.150 Redo here. 01:04.160 --> 01:08.390 Yes, redo and here. 01:11.000 --> 01:13.010 Let's get our delete this. 01:13.010 --> 01:16.280 And after that we're going to develop our search operation. 01:16.280 --> 01:26.930 So under the insert here, we're going to first we will create our template template type name, type, 01:26.930 --> 01:31.910 name T, and after that, here we will. 01:32.270 --> 01:35.450 So this search will return integer type. 01:35.450 --> 01:37.730 So index of our node here. 01:37.730 --> 01:41.570 So now integer linked list T here. 01:41.570 --> 01:46.280 And this is going to be search here, which is going to take t val here. 01:46.280 --> 01:53.420 And as you can see, Android studio is just automatically write it code for us and here. 01:55.210 --> 01:57.070 So firstly, create the condition. 01:57.070 --> 02:01.050 So if our linked list is empty, just return not found here. 02:01.060 --> 02:04.840 So in this case, not found here, the minus one here. 02:04.840 --> 02:08.650 In this case, it's going to be the not. 02:10.500 --> 02:11.040 Font. 02:14.460 --> 02:15.090 Here. 02:15.240 --> 02:23.220 So let's actually make it if my count is equal to zero. 02:23.820 --> 02:24.630 My I. 02:24.690 --> 02:30.240 If I have zero items in list, then return minus one. 02:30.240 --> 02:33.960 So if there is a no items, how can I search it right here? 02:34.590 --> 02:37.530 And after that we will need to count the index. 02:37.530 --> 02:39.000 So we will create an index here. 02:39.000 --> 02:44.010 So integer index, in this case, it's going to firstly start with the zero and after that we're going 02:44.010 --> 02:45.630 to traverse from the head node. 02:45.630 --> 02:54.690 So node T and node hit here and we will create a while loop here. 02:55.420 --> 03:02.420 To traverse until the selected value is matched with the value of the current position. 03:02.440 --> 03:04.720 Here it will look like this. 03:04.750 --> 03:05.470 Here, for example. 03:05.470 --> 03:06.130 This is one. 03:06.400 --> 03:07.030 Let's actually. 03:07.030 --> 03:07.390 Yeah. 03:07.420 --> 03:10.000 For example, this is one five. 03:11.200 --> 03:12.010 Five. 03:12.010 --> 03:14.620 Six, four. 03:15.850 --> 03:17.800 Three nine. 03:19.420 --> 03:21.490 Or, for example, 20. 03:23.300 --> 03:26.690 2029. 03:27.530 --> 03:37.520 Or and to and here, for example, if we are searching for the or for if we are searching for for here 03:37.790 --> 03:39.170 searching. 03:43.000 --> 03:43.990 Search. 03:44.980 --> 03:45.730 For here. 03:45.730 --> 03:48.130 So this while loop will continue here. 03:48.130 --> 03:56.200 If one is is one is equals to four, you know, then we'll continue to five, six, four. 03:56.200 --> 04:01.360 And here we found the for the loop will break here. 04:02.720 --> 04:06.590 Here, so the loop will not continue. 04:07.510 --> 04:11.260 And not look at here since we found the four here. 04:11.530 --> 04:15.910 So let's get started by writing our while loop now. 04:16.030 --> 04:17.020 So. 04:19.110 --> 04:22.170 While our not. 04:23.120 --> 04:23.980 Here. 04:24.170 --> 04:30.170 Node value value is not equals to our this value here. 04:30.170 --> 04:36.140 So is not equals to our value that we're going to get with the we're going to get from the parameter 04:36.140 --> 04:41.420 of our search then here, then until here. 04:41.420 --> 04:43.730 So until this value is not equals to. 04:45.080 --> 04:45.830 Value. 04:46.250 --> 04:48.080 Then keep looping here. 04:48.080 --> 04:48.410 So. 04:48.410 --> 04:50.270 Well, then keep looping. 04:50.270 --> 04:53.390 So we will increase the index by one. 04:53.390 --> 04:54.080 So we will. 04:54.080 --> 04:57.590 So we will look at other next indexes here. 04:57.590 --> 05:01.230 And after that we're going to note here. 05:01.280 --> 05:04.730 Node Node next. 05:05.270 --> 05:06.650 And here. 05:08.180 --> 05:17.600 If our node is null, if our node is null here, then it will return return minus one again. 05:17.600 --> 05:25.580 So if our count is we have nothing in our list, then it will return minus one which is not found. 05:25.580 --> 05:31.340 And if our node is null, it will also return minus one here. 05:35.630 --> 05:42.890 And after that we will just outside the while loop here, we will just return the index. 05:43.160 --> 05:45.740 Return the index here. 05:46.790 --> 05:47.930 So that's it. 05:48.080 --> 05:55.280 So again, since we need to traverse list element, the complexity of this operation here will be here. 05:55.280 --> 05:58.190 The complexity of this operation is going to be zero. 05:59.740 --> 06:02.530 And multiply by n here. 06:03.350 --> 06:06.590 Science and is our number of items that we're going to search. 06:06.590 --> 06:15.050 But however the selected value here, for example, let's create another example again here, for example. 06:16.200 --> 06:20.190 The two of us here, for example. 06:20.220 --> 06:22.110 Two, five. 06:23.120 --> 06:24.170 32. 06:25.340 --> 06:26.330 15. 06:28.840 --> 06:30.190 80 here. 06:31.900 --> 06:35.530 Three of three and nine. 06:35.560 --> 06:44.230 So, for example, for example, if we are searching for two, then we will first find this. 06:44.230 --> 06:50.800 So that is going to be our best case scenarios because it's going to be zero one here. 06:50.800 --> 06:57.610 But in the worst case scenario, for example, we have one, two, three, four, five, six, seven 06:57.610 --> 07:03.340 elements and here we are, select this here, oops, Here, let's select different color. 07:03.340 --> 07:04.420 So we will check this. 07:04.420 --> 07:10.900 Yeah, it's not equal to for example, if we are searching for nine, it's not nine naught nine naught 07:10.900 --> 07:12.940 nine naught nine here and not nine. 07:12.940 --> 07:19.300 And as you can see here, we finally found nine, which is it's going to be our worst case. 07:19.300 --> 07:22.030 So worst case. 07:23.620 --> 07:28.510 This is our worst case scenario in our application.