Breadth First Search vs Depth First Search in Hindi * BFS vs DFS in Hindi *

[0:00]breadth first search and depth first search ke beech mein ke difference ka abhyaas karne wale hain kyuki iss topic ke upar exam mein question aana must hai. Sabse pehle hum in dono ka working samjh lete hai taaki ye jo baki ke saat points hai wo aapko aur jyada acche se samjhenge. Ab sabse pehle breadth first search ka working samjh lete hai. Dekho, breadth first search kaise kaam karta hai? Let's say for example ye mera start state hai aur ye mera goal state hai. Ab breadth first search mein kya hota hai? Idhar se main searching karna chalu kar deta hu. From A to B jata hu, mujhe mera goal state nahi milta. B to C jata hu, mujhe mera goal state nahi mila. C to D jata hu, mujhe mera goal state nahi mila. D to E jata hu, goal state nahi mila. E to F jata hu, ab yahan pe finally mujhe mera goal state mil gaya. Toh basically jaise ki aap yahan pe dekh sakte ho, breadth first search search kaise karta hai? Idhar se shuru karta hai, aise jata hai and aise jata hai. Matlab basically do cheezein aap samjh sakte ho isse. Ek toh woh horizontally search karta hai ya you can say level by level search karta hai. Level zero search karega sabse pehle, fir level one search karega uske baad, then level two search karega uske baad. And then let's say for example hamara jo goal state hai yahan pe toh usko mil gaya but agar goal state third level pe hota tha toh then baad mein third level search karta tha and then usko finally goal state mil jata tha. Toh basically breadth first search aise kaam karta hai. Ab depth first search kaise kaam karta hai? Dekho. Agar let's say for example yahan pe bhi ye mera start state hai and yahan pe ye mera goal state hai. Toh depth first search kya karta hai? A se shuru karta hai, then B ke upar jata hai, yahan pe usko uska goal state nahi milta. Then D ke upar jata hai, goal state nahi mila, back track karta hai. Back track karta hai. Yahan pe jata hai, goal state nahi mila. And then E ke upar jata hai, goal state nahi mila. Toh fir back track karta hai and then finally F ke upar jata hai and yahan pe uska goal state mil gaya. Toh basically yahan pe kya ho raha hai? Depth first search ne kaise kaam kiya? A se woh B ke upar gaya and B se D ke upar gaya. Okay? And then aage kuch tha hi nahi isiliye aage woh nahi gaya. Agar aage hazaar nodes bhi hote the aise toh woh aage jata tha aakhri tak and agar usko aakhri mein kuch nahi milta tha toh fir woh back track karta tha and then woh yahan se aage gaya. Toh ab yahan pe aap kya notice kar pa rahe ho? Yahan pe aap ye notice kar pa rahe ho, ek toh ye vertically search karta hai aur ye depth mein jata hai theek hai and then depth mein agar usko kuch nahi mila toh fir woh back track karke aage badhta hai jaise ki humne yahan pe kiya. Okay? Ab hamare baki ke point samjhate hain, ab aapko bahut jyada asani hogi sari ki sari cheezein samjhne mein. Sabse pehla point, BFS ka oh god. Sabse pehla point BFS ka full form breadth first search hota hai, ye depth first search hota hai. Okay, I am very embarrassed to write this point but at the end of the day ye ek valid point hai. Agar aap exam mein likhoge toh koi bhi aapko like iske liye zero marks nahi de sakta at the end of the day valid point hi hai theek hai. Second point ke upar jump karte hai, BFS traverses the tree level wise. Jaise ki humne yahan pe discuss kiya tha ki ye horizontally ya level wise traverse karta hai. Isko humne explain kiya tha jab hum iska working dekh rahe the tab and ye DFS traverses the tree depth wise. Ye depth mein jata hai. Okay toh ye bhi humne discuss kiya tha. Third is, it works on FIFO. Ye FIFO ke upar kaam karta hai. FIFO ka matlab hota hai first in first out, matlab basically queue mein kaam karta hai. But ye kya hota hai? Ye LIFO ke upar kaam karta hai. LIFO ka matlab hota hai last in first out. Matlab stack ke upar kaam karta hai. Fourth is, requires more memory as compared to DFS. DFS ke mukable ye jyada memory consume karta hai. But DFS kam memory consume karta hai as compared to BFS. Now fifth is, it always provides shallowest path solution. Ab yahan pe jaise ki aapko maine bola tha ki ye horizontally search karta hai toh agar aapne samundar ko dekha toh shallow samundar aap kisko bolte ho? Jo jyada deep mein nahi jata ussi ko aap shallow bolte ho, right? And yahan pe cheezein shallow situation mein hi kaam kar rahi hai. Yahan pe usko deep nahi jana pad raha hai aur isiliye iske shallowest path solution dene ke chances badh jate hai. But yahan pe kya hota hai? Yahan pe usko depth mein jana padta hai. Theek hai? Agar yahan pe aage hazaar nodes honge toh usko hazaar nodes search karne padenge. Us depth mein jana padega and then agar uska aage kuch nahi mila toh fir woh back track karke aage badhega. Toh basically yahan pe kyuki woh bahut jyada depth mein ja raha hai isiliye ye shallowest path solution dega humesha iski guarantee nahi karta, right? Next point is, no back tracking is required. Jab maine iska aapko working explain kiya kya usme kabhi bhi back tracking ya back track karne ka zikr maine kiya tha? Nahi. Kyuki isme back tracking ki zarurat hi nahi padti. But iska jab working main aapko samjha raha tha tab isme humne do ya teen baar back track kiya tha. Theek hai? Kyuki isme back tracking ki zarurat padti hai agar aapko goal state tak pahunchna hai toh. Next point, BFS can never get trapped into infinite loops. Ye infinite loop mein kabhi bhi trap nahi ho sakta, but ye ho sakta hai. Kyu? Kyuki let's say for example, main aapko batata hu. Let's say for example, ye jo branch hai woh agar infinite hai, ye khatam hi nahi hone wali. And agar isne searching yahan se shuru kiya, aage gaya, aage gaya aur agar is branch mein woh aage ja raha hai search karte karte and woh kabhi bhi wapas nahi aane wala kyuki ye tabhi wapas aa sakta hai agar usko udhar dead end mila toh. But kyuki woh infinite hai aur isiliye woh kabhi wapas nahi aane wala, but iska goal state toh yahan pe hai aur kyuki woh wapas kabhi aane hi nahi wala isiliye yahan tak woh kabhi pahunch hi nahi sakta toh iska matlab woh ek infinite loop mein atak chuka hai. Aur isiliye ye point ye kehta hai ki it generally gets trapped into infinite loop. But yahan pe aisa nahi hota, yahan pe woh depth mein nahi jata, yahan pe sab cheezein horizontally hoti hai isiliye ye infinite loop mein trap nahi hota. And the eighth point is, iska example, ye example bindas aap exam mein likh sakte ho. And ye answers bhi likh dena ki answers bilkul ussi hisab se hai jis hisab se maine aapko cheezein explain ki thi. I mean agar iski baat ki toh A, B, D, A, B, D then baad mein back track karke idhar C okay then E and then F. Same. And yahan pe bhi same tha, agar ye kiya toh. Okay? Ab is subject ke notes maine aapke liye banaya hai. Notes mein aapko exam mein aane wale sare ke sare questions aur unke answers mil jayenge. Aur agar aap in answers ko exam mein likhte ho toh aapke marks bahut jyada badhne wale hai and aapko bahut acche pointers milenge. Notes kaise purchase karne hai sare ke sare details aapko description box mein niche mil jayenge. Mujhe comment section mein batao ki video kaisa laga. Ye hamara playlist hai. Yahan pe aapko is subject ke sare ke sare topics mil jayenge ya available hai. Thank you for watching this video. Have a nice day. Bye bye.