1 00:00:01,720 --> 00:00:03,370 Hey, guys, what's up? 2 00:00:03,880 --> 00:00:10,660 So today we are solving an interesting problem, so the problem statement is so given a number and given 3 00:00:10,660 --> 00:00:14,710 a number and we have to check whether this number is prime or not. 4 00:00:15,670 --> 00:00:17,500 So how do check with their numbers prime? 5 00:00:17,800 --> 00:00:19,570 So first of all, what do you mean by prime? 6 00:00:19,910 --> 00:00:22,720 So prime number is a number that has only two factors. 7 00:00:23,080 --> 00:00:24,690 One and itself. 8 00:00:26,120 --> 00:00:28,850 For example, Dhoom is a prime number, it has two factors. 9 00:00:28,880 --> 00:00:31,060 One, two, five is the prime number. 10 00:00:31,190 --> 00:00:32,090 It has two factors. 11 00:00:32,120 --> 00:00:32,990 One in five. 12 00:00:33,510 --> 00:00:34,570 Thirteen is a prime number. 13 00:00:34,580 --> 00:00:35,480 It has two factors. 14 00:00:35,510 --> 00:00:40,550 One and had been similarly, 17 is a prime number because it has two factors. 15 00:00:40,970 --> 00:00:44,750 Fifteen is not a prime number because it has more than two factors. 16 00:00:46,080 --> 00:00:46,360 OK. 17 00:00:46,660 --> 00:00:50,160 So this is not prime, this all four the frames. 18 00:00:50,710 --> 00:00:53,110 So the question is, will be given a number. 19 00:00:53,440 --> 00:00:58,220 And I have to report to the user whether that number is prime or Ligue in numbers, not prime. 20 00:00:58,690 --> 00:01:01,210 So how we can check with our number is Paymer not. 21 00:01:01,510 --> 00:01:04,360 So what I will do, I will start dividing that number by two. 22 00:01:04,930 --> 00:01:05,750 I will divide by two. 23 00:01:05,770 --> 00:01:06,720 Then I will divide by three. 24 00:01:06,790 --> 00:01:07,840 Then I will divide by four. 25 00:01:08,170 --> 00:01:11,230 And I will keep dividing on Bill and minus one. 26 00:01:12,310 --> 00:01:18,940 If out of these number, if out of all these numbers, if I get just anyone number, if I get any one 27 00:01:18,940 --> 00:01:28,030 number that divides and then I can see that the number N is not prime number. 28 00:01:28,570 --> 00:01:30,430 This is not prime either. 29 00:01:30,430 --> 00:01:33,400 Revise the number and is a prime number. 30 00:01:33,940 --> 00:01:36,610 OK, so what I need here is I will use a loop. 31 00:01:36,910 --> 00:01:43,450 So this loop will start from this loop will start from two and this loop will go till and minus one. 32 00:01:43,750 --> 00:01:44,890 And I will do eight plus. 33 00:01:44,890 --> 00:01:45,910 Plus what I will do. 34 00:01:45,940 --> 00:01:49,900 I will check if the number N is usable by I. 35 00:01:50,370 --> 00:01:53,470 I can say this number is not prime. 36 00:01:56,290 --> 00:01:57,010 A lot of eyes. 37 00:01:57,160 --> 00:01:58,570 This number is prime. 38 00:01:59,040 --> 00:02:01,600 So so let's write the code for it. 39 00:02:04,650 --> 00:02:05,730 So let's name it. 40 00:02:07,790 --> 00:02:08,010 Check. 41 00:02:08,320 --> 00:02:08,760 Fame. 42 00:02:11,010 --> 00:02:11,880 Nard CVB. 43 00:02:22,400 --> 00:02:26,410 So what I will do, I will take a No N and fundi user. 44 00:02:27,650 --> 00:02:32,390 Now our logic was we will try to divide this number in starting from two. 45 00:02:32,450 --> 00:02:33,470 So I equals two. 46 00:02:34,730 --> 00:02:39,950 While I is less than or equal to N minus one. 47 00:02:40,940 --> 00:02:41,990 Now what we have to do. 48 00:02:42,470 --> 00:02:43,240 I will check. 49 00:02:44,420 --> 00:02:49,870 I will check if the given number N is there as well by I. 50 00:02:50,720 --> 00:02:53,750 That means this number is not a frame. 51 00:02:53,810 --> 00:02:54,650 So C out. 52 00:02:56,040 --> 00:02:56,730 C out. 53 00:02:56,870 --> 00:03:00,850 This number is not prime. 54 00:03:02,200 --> 00:03:02,540 OK. 55 00:03:03,020 --> 00:03:04,850 And our work is complete. 56 00:03:04,910 --> 00:03:06,770 So I will break this loop. 57 00:03:08,370 --> 00:03:10,770 He and I will be having a plus plus. 58 00:03:13,820 --> 00:03:21,050 And if this loop this way loop got terminated naturally. 59 00:03:21,850 --> 00:03:25,160 Let me use my big statement has never been executed. 60 00:03:25,670 --> 00:03:30,590 Then I can say this number is definitely a prime number. 61 00:03:32,360 --> 00:03:32,650 OK. 62 00:03:32,990 --> 00:03:34,520 So this is all that we have to do. 63 00:03:35,540 --> 00:03:36,280 Now, let's see. 64 00:03:39,220 --> 00:03:41,230 So let's take an example. 65 00:03:41,980 --> 00:03:44,450 So let's take the example N equals four. 66 00:03:44,760 --> 00:03:44,980 OK. 67 00:03:45,060 --> 00:03:50,410 So any equals for now, I will try to divide that number by to divide the number by two. 68 00:03:50,770 --> 00:03:53,560 So for Marda, two equals zero. 69 00:03:53,800 --> 00:03:54,190 Yes. 70 00:03:54,790 --> 00:03:55,710 The condition is true. 71 00:03:56,170 --> 00:03:57,390 See out not prime. 72 00:03:57,760 --> 00:04:02,140 So I reprint Nart prime and break. 73 00:04:02,740 --> 00:04:05,010 Break means come out of the loop. 74 00:04:05,320 --> 00:04:07,870 So I will reach at line number 19. 75 00:04:08,200 --> 00:04:11,030 I will check if I is ever live either way. 76 00:04:11,100 --> 00:04:11,740 If I is to. 77 00:04:12,040 --> 00:04:13,960 So if I equals equals four. 78 00:04:14,110 --> 00:04:15,280 No this is not true. 79 00:04:15,730 --> 00:04:17,050 So I will reach here. 80 00:04:17,140 --> 00:04:18,010 Return zero. 81 00:04:18,210 --> 00:04:19,010 So I'm out for days. 82 00:04:19,150 --> 00:04:19,990 Not fine. 83 00:04:20,830 --> 00:04:21,100 OK. 84 00:04:21,520 --> 00:04:23,790 Now let us take the case of a prime number. 85 00:04:25,490 --> 00:04:26,370 So what will happen? 86 00:04:27,390 --> 00:04:29,830 So let's see, And equals five. 87 00:04:29,940 --> 00:04:31,110 So five is a prime number. 88 00:04:31,140 --> 00:04:32,010 So what will happen? 89 00:04:33,160 --> 00:04:34,840 I will try to do at the number by two. 90 00:04:35,050 --> 00:04:38,230 So five more do it equals zero. 91 00:04:38,320 --> 00:04:39,510 No other condition is false. 92 00:04:40,000 --> 00:04:43,830 Then I will try to do that number by three condition is false. 93 00:04:44,380 --> 00:04:47,410 Then I will try to reduce the number by for the condition is false. 94 00:04:47,740 --> 00:04:48,480 Now what will happen. 95 00:04:48,490 --> 00:04:50,170 The value of five will become five. 96 00:04:52,320 --> 00:04:56,240 As the video fight becomes, it goes to end this loop this way loop. 97 00:04:56,580 --> 00:04:58,800 Well, it got terminated naturally. 98 00:04:59,670 --> 00:05:03,030 Okay, so a big statement has never been executed. 99 00:05:03,360 --> 00:05:06,410 So I will reach here is five. 100 00:05:06,540 --> 00:05:07,740 Equals equals five. 101 00:05:07,800 --> 00:05:09,360 Yet the condition is to print. 102 00:05:10,070 --> 00:05:13,620 So for any equals five miles for this brain which is hundred percent. 103 00:05:13,650 --> 00:05:14,130 Correct. 104 00:05:14,880 --> 00:05:15,170 OK. 105 00:05:15,930 --> 00:05:18,240 So this big is very important. 106 00:05:18,300 --> 00:05:21,070 If you will not try to break your heart would really be wrong. 107 00:05:22,990 --> 00:05:29,880 OK, so one more time, if there is no eye that divides, and I will point out not prime. 108 00:05:30,150 --> 00:05:32,130 And I will break the loop. 109 00:05:32,610 --> 00:05:32,840 OK. 110 00:05:33,180 --> 00:05:34,380 So I will break the loop. 111 00:05:34,410 --> 00:05:36,630 I will likely reach line number 19. 112 00:05:37,110 --> 00:05:41,250 And this condition will definitely be false if Blake's treatment is executed. 113 00:05:41,610 --> 00:05:43,140 This condition will be false. 114 00:05:43,590 --> 00:05:47,550 And if the number is prime, then this condition will be false. 115 00:05:47,980 --> 00:05:50,840 And I will become equals to end the violence. 116 00:05:50,910 --> 00:05:53,810 We've got a murder naturally and I will end. 117 00:05:53,850 --> 00:05:55,290 This condition would become true. 118 00:05:55,420 --> 00:05:56,580 Then the number is prime. 119 00:05:57,120 --> 00:05:59,520 Let's see whether our goal is working, correct or not. 120 00:05:59,850 --> 00:06:00,640 For example. 121 00:06:00,750 --> 00:06:01,170 Five. 122 00:06:01,260 --> 00:06:02,750 So five is a prime number. 123 00:06:05,850 --> 00:06:08,780 So Tartine is also a prime number. 124 00:06:10,930 --> 00:06:13,870 So Ford is not prime. 125 00:06:16,400 --> 00:06:19,430 Similarly, Ben is not prime. 126 00:06:21,050 --> 00:06:26,720 OK, so this is the code for checking whether the given number is a prime number or not. 127 00:06:27,170 --> 00:06:29,330 So if you have any doubt, feel free to ask. 128 00:06:29,720 --> 00:06:29,980 OK. 129 00:06:30,110 --> 00:06:31,400 So this is it for this video. 130 00:06:31,580 --> 00:06:32,150 Thank you.