1 00:00:01,430 --> 00:00:03,050 Hello everyone welcome to the session. 2 00:00:03,050 --> 00:00:08,070 So in this session what we will do so we will try to solve one more problem with the help of the occasion. 3 00:00:08,120 --> 00:00:10,980 So the name of the problem is printed numbers. 4 00:00:11,120 --> 00:00:13,850 Okay so we will cause this problem. 5 00:00:13,940 --> 00:00:16,190 We will solve this problem with the help of the equation. 6 00:00:16,190 --> 00:00:17,960 So what this problem suggests. 7 00:00:18,320 --> 00:00:20,950 So if the value of minus five. 8 00:00:21,080 --> 00:00:22,160 What would I have to do. 9 00:00:22,400 --> 00:00:27,260 So I have to print the numbers from 1 2 n so if the value of find his wife I will print the number 1 10 00:00:27,450 --> 00:00:29,510 2 3 4 5. 11 00:00:29,600 --> 00:00:33,920 If the value of and is three I will print the numbers one two three. 12 00:00:33,930 --> 00:00:38,010 Okay so what I have to do I have to write a function print. 13 00:00:38,120 --> 00:00:41,780 And and this print and function what it will do it will print the number. 14 00:00:41,780 --> 00:00:43,720 It will start printing from 1 Bill. 15 00:00:44,200 --> 00:00:44,550 Okay. 16 00:00:45,110 --> 00:00:46,630 So this is the bulk of dysfunction. 17 00:00:46,640 --> 00:00:50,630 We can solve this problem very easily using the for loop all the while loop but we have to solve this 18 00:00:50,630 --> 00:00:51,710 problem using a regression. 19 00:00:52,220 --> 00:00:57,350 So using regression what I have to do if I want to solve the problem for n then i have to solve the 20 00:00:57,350 --> 00:00:59,200 problem for the smaller end. 21 00:00:59,240 --> 00:00:59,720 Okay. 22 00:00:59,810 --> 00:01:03,160 So what this print n function will do. 23 00:01:03,290 --> 00:01:07,220 So this print n function it will print the number from 1 2. 24 00:01:07,270 --> 00:01:07,720 Okay. 25 00:01:07,730 --> 00:01:14,240 So this print then function it will print the numbers from 1 2 and so can I write like this. 26 00:01:15,530 --> 00:01:23,120 So what this print and minus one function will do so print and function its job is to print the numbers 27 00:01:23,480 --> 00:01:28,740 starting from one deal and what this print and minus one will do. 28 00:01:28,840 --> 00:01:33,670 So it will start printing the number from one bill and minus one. 29 00:01:33,700 --> 00:01:34,310 Okay. 30 00:01:34,330 --> 00:01:42,080 And this is our goal and this this is and this will be the output of and minus one function. 31 00:01:42,080 --> 00:01:45,150 Then after printing that and minus one we will print n. 32 00:01:46,020 --> 00:01:46,560 Okay. 33 00:01:46,670 --> 00:01:50,320 After printing and minus one we will print and that's done so. 34 00:01:50,540 --> 00:01:52,270 And this time will also get printed. 35 00:01:52,280 --> 00:01:54,810 So these two will become equal. 36 00:01:54,920 --> 00:01:55,190 Okay. 37 00:01:55,220 --> 00:01:59,690 So this will be our recursive case simple enough. 38 00:01:59,710 --> 00:02:00,020 Okay. 39 00:02:00,520 --> 00:02:06,020 So let's write the code for this. 40 00:02:06,070 --> 00:02:11,470 So first of all you're too little return type return type will be void because I'm not I'm not returning 41 00:02:11,470 --> 00:02:13,050 anything I'm basically printing. 42 00:02:13,100 --> 00:02:18,650 Okay so I have to print what it will take it will take I integer s argument. 43 00:02:18,780 --> 00:02:19,020 Okay. 44 00:02:19,030 --> 00:02:27,710 So first of all what will be the base case what do with the base case so base case is the smallest smallest 45 00:02:27,710 --> 00:02:33,530 problem whose solution we already know so the smallest problem will be if the value of any 0. 46 00:02:34,400 --> 00:02:39,860 So if the value of an Israel would have to do what I have to print I do not have to print anything. 47 00:02:39,860 --> 00:02:40,400 Okay. 48 00:02:40,460 --> 00:02:43,250 If the value of an Israel do not print anything. 49 00:02:43,250 --> 00:02:46,380 So this would be our base case because I have to start printing from 1. 50 00:02:46,430 --> 00:02:50,980 You can see here we have to start printing from 1. 51 00:02:50,990 --> 00:02:53,920 If the value of and is 0 we will not print anything. 52 00:02:54,050 --> 00:02:54,580 Okay. 53 00:02:54,650 --> 00:02:56,130 You have to start printing from 1. 54 00:02:56,210 --> 00:03:02,110 You can also write the base case for any question also if the value of land is 1 then print 1. 55 00:03:02,180 --> 00:03:02,660 Okay. 56 00:03:03,080 --> 00:03:08,210 So as you wish you can as you wish you can modify the code. 57 00:03:08,270 --> 00:03:08,540 Okay. 58 00:03:08,540 --> 00:03:12,140 So the return type is void hence I am not understanding anything. 59 00:03:12,140 --> 00:03:13,000 Okay. 60 00:03:13,160 --> 00:03:20,090 So if the value of any 0 then do not print anything otherwise first what we have to do recursive case 61 00:03:21,080 --> 00:03:27,870 so recursive case will be so this function print function it prints the number from 1 2. 62 00:03:27,880 --> 00:03:32,920 And now I'm calling this print function for and minus 1. 63 00:03:32,930 --> 00:03:37,430 What will happen our numbers will get printed from 1 to 1. 64 00:03:37,460 --> 00:03:46,630 So what will output of this line this line will print the numbers starting from 1 bill and minus 1. 65 00:03:46,660 --> 00:03:52,150 Okay so this is the this is our output a line number eleven. 66 00:03:52,150 --> 00:03:52,410 Okay. 67 00:03:52,420 --> 00:03:55,590 So this is our output to line number eleven. 68 00:03:55,780 --> 00:03:57,750 Now our third thing. 69 00:03:57,790 --> 00:04:01,930 So the calculation part what I have to do I have to print and it's dumb. 70 00:04:02,480 --> 00:04:04,230 Okay. 71 00:04:04,300 --> 00:04:10,680 Now let's print Okay so this is our output. 72 00:04:10,680 --> 00:04:14,010 Okay so this print function what is it. 73 00:04:14,100 --> 00:04:18,060 What it does is it prints the number from 1 2 in print and minus 1. 74 00:04:18,050 --> 00:04:24,180 It will print the number from 1 to N minus 1 and then I am printing the anything but okay now let's 75 00:04:24,180 --> 00:04:29,230 call this function let's call this print function for let's five. 76 00:04:29,270 --> 00:04:29,530 Okay. 77 00:04:31,030 --> 00:04:32,130 Now let's send in our file. 78 00:04:32,500 --> 00:04:37,230 Okay so this function is not returning anything so I have to call this function. 79 00:04:37,360 --> 00:04:41,220 I cannot write you out okay because this function audit ending anything. 80 00:04:41,260 --> 00:04:42,220 Now let's send our file 81 00:04:45,380 --> 00:04:47,860 so the -- that output 1 2 3 4 and 5. 82 00:04:48,050 --> 00:04:53,090 Okay so our code is working fine now after writing the code what we have to do we have to make the diagram. 83 00:04:53,210 --> 00:04:55,890 We have to brighten our code so we can understand it better. 84 00:04:56,270 --> 00:04:57,950 Okay so print 5. 85 00:04:57,980 --> 00:04:59,300 The value of an is 5. 86 00:04:59,390 --> 00:05:01,610 Okay so this is 5. 87 00:05:02,300 --> 00:05:03,670 So I am writing the output here. 88 00:05:03,680 --> 00:05:04,730 I will write output here. 89 00:05:04,760 --> 00:05:18,490 Okay so 5 will call on 4 4 will call on 3 3 will call on 2 2 will call on 1 1 will call on 0. 90 00:05:18,490 --> 00:05:20,270 So if the value of any 0. 91 00:05:20,290 --> 00:05:21,000 What I'm doing. 92 00:05:21,020 --> 00:05:21,480 Return. 93 00:05:21,880 --> 00:05:22,940 So I will come here. 94 00:05:22,960 --> 00:05:24,000 We're done. 95 00:05:24,000 --> 00:05:29,080 Okay so when was waiting at line number eleven when was waiting at line number eleven. 96 00:05:29,080 --> 00:05:35,890 Now I will reach your line number 13 C out and okay so add at this line what will happen C out and so 97 00:05:35,890 --> 00:05:37,250 when we'll get printed. 98 00:05:37,570 --> 00:05:40,570 Now you can write a written statement here also. 99 00:05:40,600 --> 00:05:41,090 Okay. 100 00:05:41,140 --> 00:05:42,550 The return statement this is optional. 101 00:05:42,550 --> 00:05:43,300 So what will happen. 102 00:05:43,300 --> 00:05:45,380 I will come here okay. 103 00:05:45,420 --> 00:05:51,710 So the value of this to so do was also waiting at line number eleven then CO2. 104 00:05:51,720 --> 00:05:56,130 So two will get printed so one get printed first then 2 printed. 105 00:05:56,130 --> 00:05:57,380 Then you're done. 106 00:05:57,420 --> 00:05:58,680 I will write the line you're done. 107 00:05:58,740 --> 00:06:01,300 I will write the statement then but this is optional. 108 00:06:01,350 --> 00:06:03,980 Okay because the code ends at line number 15. 109 00:06:03,990 --> 00:06:05,690 So I think Red done is optional here. 110 00:06:06,560 --> 00:06:09,260 So the value of industry now tables get printed. 111 00:06:09,290 --> 00:06:12,590 So write down the value of minus 4 4 will get printed. 112 00:06:12,770 --> 00:06:18,010 The value of minus 5 5 will get printed and then find literate and I will reach the mean and then return 113 00:06:18,090 --> 00:06:19,490 the other program will be all what. 114 00:06:19,550 --> 00:06:20,820 And this will be our output. 115 00:06:21,470 --> 00:06:23,790 Okay so you might. 116 00:06:24,050 --> 00:06:25,360 So you might have confusion. 117 00:06:25,370 --> 00:06:26,770 So I am returning. 118 00:06:27,170 --> 00:06:28,370 I am writing return here. 119 00:06:28,370 --> 00:06:28,900 Okay. 120 00:06:28,940 --> 00:06:30,090 It will an artifact Delacorte. 121 00:06:30,110 --> 00:06:31,500 I've got will still work fine. 122 00:06:34,030 --> 00:06:37,050 So our output is still one two three four five. 123 00:06:37,150 --> 00:06:37,830 Okay. 124 00:06:37,970 --> 00:06:40,000 Java code is working fine. 125 00:06:40,000 --> 00:06:48,080 Now one more thing so here I abandon them both in ascending order. 126 00:06:48,260 --> 00:06:52,880 I am printing the numbers in descending order 1 2 and now what if I print I want to print the number 127 00:06:52,880 --> 00:06:53,890 in descending order. 128 00:06:54,050 --> 00:07:00,600 For example if the value of and is 5 I want to print 5 4 3 2 and when. 129 00:07:00,610 --> 00:07:02,750 Okay this is how I want to print the number. 130 00:07:02,750 --> 00:07:05,090 Basically I want to print the number in descending order. 131 00:07:05,900 --> 00:07:13,430 Okay so what we will do let's say I am writing print to function so print to what it will take it will 132 00:07:13,430 --> 00:07:19,490 take and as input and its work as to what it will do it will print the numbers in descending order five 133 00:07:19,490 --> 00:07:21,280 four three two and one. 134 00:07:22,040 --> 00:07:27,090 Okay so first of all what I will do I will print and okay. 135 00:07:27,120 --> 00:07:30,530 Because the value of this 5 5 is getting printed first. 136 00:07:30,530 --> 00:07:37,490 So first of all I will print that number and and then I will call the function and minus 1. 137 00:07:37,550 --> 00:07:38,200 So what. 138 00:07:38,240 --> 00:07:44,600 And minus 1 will do so and minus 1 will start bringing the numbers from and minus 1 then and minus 2 139 00:07:45,080 --> 00:07:46,050 L1. 140 00:07:46,350 --> 00:07:47,050 Okay. 141 00:07:47,060 --> 00:07:53,110 And first of all and we'll get printed and our book was also the same. 142 00:07:53,240 --> 00:07:55,790 We have to print the numbers in descending order. 143 00:07:55,790 --> 00:07:59,970 Okay so first I have to print n and then I will call. 144 00:07:59,990 --> 00:08:02,500 I will call the same function here. 145 00:08:02,630 --> 00:08:04,130 It will be the opposite of this. 146 00:08:04,130 --> 00:08:11,030 So first I was calling and minus 1 and then I was printing and but here first I will print n and then 147 00:08:11,120 --> 00:08:12,470 I will call and minus 1. 148 00:08:12,800 --> 00:08:16,310 Okay so basically defending or there will be the opposite of the ascending order. 149 00:08:16,950 --> 00:08:17,440 Okay. 150 00:08:17,600 --> 00:08:20,000 So what I will do. 151 00:08:20,000 --> 00:08:22,470 Let's write print to function. 152 00:08:22,460 --> 00:08:23,720 Let's copy discord 153 00:08:26,790 --> 00:08:29,490 so this is print to function. 154 00:08:29,490 --> 00:08:33,180 Now what I have to do I have to just change the order of these two lines. 155 00:08:33,240 --> 00:08:35,190 So first I will print n 156 00:09:01,270 --> 00:09:01,690 okay. 157 00:09:01,800 --> 00:09:05,450 So this will be our print to function so print to function what it does is. 158 00:09:05,530 --> 00:09:07,030 So this is our base case. 159 00:09:07,050 --> 00:09:11,770 Now first I will print n and then I will call and minus 1. 160 00:09:11,790 --> 00:09:14,090 So sorry this will be print too. 161 00:09:14,190 --> 00:09:15,930 Okay print to function. 162 00:09:15,930 --> 00:09:24,160 So what this function will do it will start printing the numbers from N minus 1 bill when. 163 00:09:24,230 --> 00:09:27,670 Okay so this will be the output of this line. 164 00:09:27,670 --> 00:09:34,480 But before the output of this line I am printing and OK now let's call print to function. 165 00:09:34,480 --> 00:09:39,850 So I am calling pen to function and I'm giving five his input so our output will be five four three 166 00:09:39,850 --> 00:09:40,630 two and one. 167 00:09:40,690 --> 00:09:43,660 OK so let's write a novel called 168 00:09:46,620 --> 00:09:49,090 so all our output is 5 4 2 2 and 1. 169 00:09:49,110 --> 00:09:53,580 Now after writing the code what we have to do we have to do that and have a code so that we can understand 170 00:09:53,580 --> 00:09:55,080 what is going on here. 171 00:09:55,110 --> 00:09:55,580 Okay. 172 00:09:55,710 --> 00:09:57,210 So the value of end is five. 173 00:09:57,580 --> 00:09:59,660 Okay so this is five. 174 00:09:59,730 --> 00:10:01,650 And I will write my output here. 175 00:10:01,800 --> 00:10:05,250 Okay so 5 is not close to zero C out. 176 00:10:05,250 --> 00:10:11,860 And so five will get printed and then I am calling print to function with the value in minus one. 177 00:10:11,880 --> 00:10:12,390 Okay. 178 00:10:12,570 --> 00:10:17,550 So the value of this food for is not too close to zero C out and so forth will get printed. 179 00:10:17,730 --> 00:10:20,650 Then we are calling with a smaller function. 180 00:10:20,670 --> 00:10:24,830 Okay I will call entre then t will get printed. 181 00:10:24,830 --> 00:10:31,660 I will call on when I will call in to do is not close to zero then I will print to then to really call 182 00:10:31,660 --> 00:10:32,940 on 1. 183 00:10:32,950 --> 00:10:35,290 So 1 is not close to zero. 184 00:10:35,290 --> 00:10:41,920 So I will print one then I will call on zero so zero equals zero then I have what I will do I will have 185 00:10:41,920 --> 00:10:46,840 done so I will have done so when I was waiting at line number 26. 186 00:10:46,840 --> 00:10:51,200 Okay this one was waiting at line number 26 then return. 187 00:10:51,390 --> 00:10:52,440 So it is done. 188 00:10:52,540 --> 00:10:55,000 Who was also waiting at line number 26. 189 00:10:55,150 --> 00:10:57,630 And then you're done so I will are done. 190 00:10:57,640 --> 00:10:59,960 He was waiting at Lam 9 number 26. 191 00:11:00,130 --> 00:11:01,470 Then it will get done. 192 00:11:01,560 --> 00:11:03,510 Ford was also waiting at number 26. 193 00:11:03,520 --> 00:11:05,050 Then you're done. 194 00:11:05,260 --> 00:11:08,140 And then five was also waiting at line number 26. 195 00:11:08,140 --> 00:11:13,620 And then you're done so get it done so and this is our output five four three two one. 196 00:11:13,690 --> 00:11:14,050 Okay. 197 00:11:14,920 --> 00:11:18,460 So I hope you understand the code how it is working. 198 00:11:18,490 --> 00:11:18,990 Okay. 199 00:11:19,060 --> 00:11:22,640 So writing this down part writing this written statement is optional here. 200 00:11:22,660 --> 00:11:24,370 If you want you can remove it also. 201 00:11:24,370 --> 00:11:25,690 Okay. 202 00:11:26,320 --> 00:11:33,310 For example let's remove this line and then also have a quota of accord will work because the function 203 00:11:33,340 --> 00:11:38,560 ends here and if the function ended it automatically means that are done okay with the void. 204 00:11:38,560 --> 00:11:40,340 You have option to return. 205 00:11:40,720 --> 00:11:44,160 This is optional here but writing return here is mandatory. 206 00:11:44,170 --> 00:11:44,830 Okay. 207 00:11:44,830 --> 00:11:48,630 Writing the written statement inside the f is mandatory. 208 00:11:48,640 --> 00:11:57,420 Okay so this done is compulsory otherwise what will happen if I will order write the return statement. 209 00:11:57,420 --> 00:11:58,010 What will happen. 210 00:11:58,020 --> 00:12:00,990 I will come at line number 22 which is wrong. 211 00:12:00,990 --> 00:12:01,610 Okay. 212 00:12:01,860 --> 00:12:04,250 So writing that are done is mandatory here. 213 00:12:06,930 --> 00:12:09,050 But this is done is optional. 214 00:12:09,120 --> 00:12:09,640 Okay. 215 00:12:11,930 --> 00:12:14,020 And also this are done is optional. 216 00:12:16,250 --> 00:12:18,490 Now I command out the certain part. 217 00:12:18,500 --> 00:12:21,670 Now if we will run our program our program will still work fine. 218 00:12:21,820 --> 00:12:23,630 Our output to live a full crew to anyone. 219 00:12:23,870 --> 00:12:31,700 Okay so I hope you understand why this redundant mandatory I am led straight to so it is a value of 220 00:12:31,760 --> 00:12:32,390 industry. 221 00:12:32,410 --> 00:12:35,420 Let's say I am calling in to function what the value of industry. 222 00:12:35,730 --> 00:12:39,530 So 3 what will happen 3 will call on 2 2 will call and 1. 223 00:12:39,620 --> 00:12:42,930 Now one will call and zero so zero equals zero. 224 00:12:42,950 --> 00:12:46,370 So if you will not write the return statement what will happen. 225 00:12:46,370 --> 00:12:50,040 So zero will come here see out zero so zero will get. 226 00:12:50,060 --> 00:12:51,290 This is our output. 227 00:12:51,380 --> 00:12:52,170 So what will happen. 228 00:12:52,160 --> 00:12:56,380 Zero will get painted Okay so this is brand to function. 229 00:12:56,390 --> 00:12:57,200 So what will happen. 230 00:12:57,200 --> 00:12:59,240 Our output is 3 to 1. 231 00:12:59,570 --> 00:13:01,740 Now what will happen the value of n is zero. 232 00:13:01,850 --> 00:13:02,900 So zero equals zero. 233 00:13:02,900 --> 00:13:05,630 But if the return statement is not here then what will happen. 234 00:13:05,630 --> 00:13:12,590 I will come at 9 number 23 so 0 1 get printed then I what I will do I will call on it to function and 235 00:13:12,590 --> 00:13:13,100 minus 1. 236 00:13:13,130 --> 00:13:19,460 So it will call on minus 1 then minus 1 will get printed it will equal and minus 2 it will equal and 237 00:13:19,460 --> 00:13:20,600 minus 3 and so on. 238 00:13:20,600 --> 00:13:23,750 Basically infinite loop problem will be there. 239 00:13:23,750 --> 00:13:25,700 Okay so infinite loop problem will be there. 240 00:13:25,700 --> 00:13:27,750 That's why this return is mandatory here. 241 00:13:27,770 --> 00:13:29,300 If this are done is there what will happen. 242 00:13:29,300 --> 00:13:30,470 I will return from zero. 243 00:13:31,000 --> 00:13:31,250 Okay. 244 00:13:31,260 --> 00:13:33,720 And this will not happen. 245 00:13:33,830 --> 00:13:38,470 Okay so this return is mandatory and it is this written is optional. 246 00:13:38,690 --> 00:13:38,990 Okay. 247 00:13:42,320 --> 00:13:45,440 And similarly for this one also Fort Bend function. 248 00:13:45,440 --> 00:13:47,020 Okay. 249 00:13:47,480 --> 00:13:48,500 What will happen. 250 00:13:48,500 --> 00:13:51,830 Suppose the value of and is 3. 251 00:13:52,040 --> 00:13:54,710 Now what will happen and is not close to zero. 252 00:13:54,710 --> 00:13:56,890 This this is our output. 253 00:13:56,890 --> 00:13:58,490 I am calling one smaller part. 254 00:13:58,490 --> 00:14:03,400 So 2 2 will call on 1 1 will call on 0. 255 00:14:03,470 --> 00:14:05,310 Okay so zero equals zero. 256 00:14:05,330 --> 00:14:07,640 So if the return statement is data what will happen. 257 00:14:07,640 --> 00:14:11,630 I will come at 1 and then one will get printed. 258 00:14:11,630 --> 00:14:16,750 But if this written statement is not there what will happen. 259 00:14:16,970 --> 00:14:18,510 What will happen when I call on. 260 00:14:18,520 --> 00:14:19,690 It also the requisite. 261 00:14:19,760 --> 00:14:21,080 The written statement is not there. 262 00:14:21,110 --> 00:14:23,200 Then I will come here at line number eleven. 263 00:14:23,210 --> 00:14:29,080 I will call minus 1 then minus and will call on minus 2 minus 2 will call on minus 3 and so on. 264 00:14:29,090 --> 00:14:31,720 Basically infinite loop problem will be there. 265 00:14:31,760 --> 00:14:33,670 That's why return is mandatory here. 266 00:14:33,680 --> 00:14:35,030 Okay. 267 00:14:35,060 --> 00:14:38,190 Inside the base case returns treatment is mandatory. 268 00:14:38,240 --> 00:14:38,450 Okay. 269 00:14:38,450 --> 00:14:40,520 Remember this thing. 270 00:14:40,520 --> 00:14:41,950 So I hope you understood the school. 271 00:14:42,300 --> 00:14:43,300 Okay thank you.