I have collected resources (scattered ones...) over internet and tried to bring it under one blog.....contributions are heartly welcomed..... :) Following are the links to all possible resources required for Competitive programming::::::::::
- https://www.quora.com/What-are-the-best-websites-with-algorithm-practice-problems
- https://www.quora.com/Where-can-I-find-difficult-algorithm-data-structure-problems
- https://www.quora.com/Who-are-some-of-the-programmers-on-GitHub-to-learn-from
- https://www.quora.com/Who-are-the-best-coders-to-follow-on-GitHub
- http://ch24.org/
- https://coj-forum.uci.cu/viewforum.php?f=42
- https://www.topcoder.com/members/a06/
- https://github.com/aalhour/C-Sharp-Algorithms
- https://projecteuler.net/
- https://github.com/absnaik810/SPOJ-Repository
- https://www.quora.com/topic/ACM-International-Collegiate-Programming-Contest-ICPC
- http://www.geeksforgeeks.org/tag/acm-icpc/
- https://icpcarchive.ecs.baylor.edu/
- http://judge.u-aizu.ac.jp/onlinejudge/register.jsp?state=0
- http://judge.u-aizu.ac.jp/onlinejudge/
- https://open.kattis.com/users/akash-kandpal#
- http://azspcs.com/
- https://contest.yandex.com/algorithm2015/
- https://handong1587.github.io/algorithm_and_data_structure/2015/07/01/resourses.html
- https://www.quora.com/topic/Algorithms
- http://petr-mitrichev.blogspot.com/2009/10/gennady-korotkevich.html
- http://eulercoder.me/AlgoWiki/
- https://www.kaggle.com/account/authenticate/google/return#
- http://codeforces.me/blog/entry/23054
- https://www.commonlounge.com/community/c3f97b04684649b1947803b817be5b4b
- https://github.com/ashim888/dataStructureAndAlgorithm
- http://codeforces.me/blog/entry/43578?locale=en
- https://discuss.codechef.com/questions/64426/awesome-resource-for-ds-and-algorithms
- https://www.codechef.com/problems/school
- https://www.commonlounge.com/discussion/97e9927870d84b51a7dc5d4a52d5434d/main
- http://shivamkhandelwal.in/beginners-guide-to-competitive-programming/
- https://confluence.atlassian.com/bitbucket/bitbucket-tutorials-teams-in-space-training-ground-755338051.html
- https://github.com/bnmnetp/pythonds
- https://www.urionlinejudge.com.br/judge/en/categories
- https://en.wikipedia.org/wiki/Central_European_Olympiad_in_Informatics
- http://codeforces.me/
- http://www.hpcodewars.org/
- http://codeluli.blogspot.in/
- http://coj.uci.cu/index.xhtml
- https://www.codechef.com/contests
- https://www.quora.com/topic/Competitive-Programming
- https://machlearner.wordpress.com/resources/
- https://www.quora.com/Competitive-Programming-How-do-I-practice-smartly
- https://www.quora.com/Competitive-Programming-What-is-the-best-way-to-progress-through-practice-problems-on-CodeChef-SPOJ-TopCoder-etc
- http://www.competitiveprogrammingnetwork.com/
- https://github.com/Michael0x2a/curated-programming-resources/blob/master/resources.md
- http://tunedit.org/challenges
- https://www.commonlounge.com/community/9dcdd386cc28446695305db00d2de532
- http://justforprogrammers.blogspot.in/2015/12/downgrade-from-marshmallow-to-lollipop.html
- http://www.infoarena.ro/downloads
- https://github.com/esbanarango/Competitive-Programming
- https://github.com/EvgenyKarkan/EKAlgorithms
- https://www.quora.com/For-an-ACM-beginner-how-should-I-start
- https://en.wikipedia.org/wiki/Gennady_Korotkevich
- https://gist.github.com/sharmaeklavya2/5299a4cd059a6f6f8699
- https://github.com/gitvipin/LeetSol
- https://www.google-melange.com/archive/
- http://www.hackathon.io/events
- https://www.quora.com/HackerRank-What-are-the-coding-contests-sites-where-companies-hire-from
- http://ww35.hacktissite.org/
- https://github.com/haoel/leetcode
- https://bitbucket.org/harrypotter0/
- https://github.com/haseebr/competitive-programming
- https://dmoj.ca/
- https://summerofcode.withgoogle.com/
- https://discuss.leetcode.com/
- https://www.quora.com/How-can-I-become-good-at-competitive-programming-Are-there-any-courses-that-will-take-me-one-step-forward-before-I-start-doing-SPOJ-or-TopCoder-problems
- https://www.quora.com/How-can-I-improve-in-competitive-programming
- https://www.reddit.com/r/learnprogramming/comments/1cj4h4/how_do_i_get_better_at_competitive_programming/
- https://www.quora.com/How-do-I-prepare-for-ACM-ICPC-regional
- https://www.quora.com/How-do-I-prepare-for-ACM-ICPC
- https://www.quora.com/How-should-I-prepare-for-ACM-ICPC
- https://www.quora.com/How-should-one-prepare-for-coding-competitions-from-scratch-who-has-just-basic-knowledge-of-programming-in-C-and-C++
- https://www.quora.com/How-should-we-start-preparation-for-ACM-ICPC
- http://codeforces.me/blog/entry/11948
- http://www.droidopinions.com/how-to-downgrade-lg-g4-h815-to-5-1-1-lollipop/
- http://www.geeksforgeeks.org/how-to-prepare-for-acm-icpc/
- https://www.hackerearth.com/ama/i-am-lalit-kundu-algorithmist-programmer-acm-icpc-15-kgp-winner-ask-me-anything/
- https://www.quora.com/Im-preparing-for-the-ACM-ICPC-2016-what-should-be-the-perfect-strategy-and-how-much-time-should-I-practice-daily
- http://icfpc2016.blogspot.in/
- https://www.quora.com/If-I-want-to-start-practicing-on-TopCoder-should-I-start-with-the-very-first-problems-If-not-from-which-problem-should-I-begin
- http://shygypsy.com/acm/
- https://www.innocentive.com/ar/challenge/browse
- https://www.commonlounge.com/community/e4aac00a033a40ec96657906c6e1b43c?action=community-join#_=_
- https://www.commonlounge.com/community/e4aac00a033a40ec96657906c6e1b43c?action=community-join
- https://en.wikipedia.org/wiki/International_Olympiad_in_Informatics
- https://ipsc.ksp.sk/
- https://www.interviewbit.com/dashboard/#
- http://ioi2017.org/
- https://www.hackerearth.com/practice/notes/iterative-tree-traversals/
- http://www.lightoj.com/register_user.php
- http://www.lightoj.com/login_main.php
- https://github.com/karan/Projects
- https://open.kattis.com/
- http://www.kurniady.net/
- http://blog.hackerearth.com/2013/09/competitive-programming-getting-started_11.html
- http://blog.mashape.com/list-of-40-tutorials-on-how-to-create-an-api/
- https://github.com/lnishan?tab=repositories
- https://github.com/lnishan/awesome-competitive-programming
- https://github.com/lnishan/cheat-sheet
- https://www.challenge.gov/login/
- https://github.com/lucasviola/competitive-programming-resources
- https://discuss.leetcode.com/category/12/median-of-two-sorted-arrays?sort=votes
- https://www.topcoder.com/getting-started/
- https://github.com/miguelarauj1o/GoogleCalendarQuickStart
- https://github.com/miguelarauj1o/URI
- https://www.commonlounge.com/community/cc63cd88d6644ce99cfb1af8b0e1350f
- http://it-edu.mipt.ru/en/fall_training_2016
- http://it-edu.mipt.ru/en/spring_training_2016
- http://codeforces.me/blog/entry/16245
- http://codeforces.me/blog/entry/10480
- https://www.hackerearth.com/practice/notes/trending/
- https://github.com/marioyc/Online-Judge-Solutions/tree/master/Timus%20Online%20Judge
- https://github.com/palcu/algo
- https://code.google.com/codejam/contests.html
- https://github.com/pathikrit/Quora-Challenges
- https://en.wikipedia.org/wiki/Petr_Mitrichev
- https://github.com/phishman3579/java-algorithms-implementation
- https://github.com/prakhar1989/Algorithms
- https://github.com/prakharcode/Algo_Ds_Notes
- http://acm.timus.ru/problemset.aspx
- https://leetcode.com/problemset/algorithms/#
- http://www.programming-challenges.com/pg.php?page=index
- https://www.quora.com/challenges
- https://www.hackerearth.com/challenges/
- https://www.codechef.com/#
- http://codeforces.me/blog/entry/11437
- http://www.programmr.com/
- http://psyho.gg/
- https://github.com/ramswaroop/Algorithms-and-Data-Structures-in-Java
- https://github.com/raywenderlich/swift-algorithm-club
- https://github.com/yogi2442/repo/tree/master/spoj
- https://github.com/rodrigoalvesvieira/competitive-programming
- https://github.com/RunestoneInteractive/pythonds
- https://discuss.leetcode.com/topic/30746/share-some-analysis-and-explanations
- https://www.hacking-lab.com/user/login/index.html
- https://www.quora.com/topic/Software-Engineering
- https://www.hackerrank.com/domains
- http://www.spoj.com/problems/classical/
- http://www.spoj.com/users/tourist/
- http://www.sgi.com/tech/stl/
- https://www.commonlounge.com/community/668b60793e4747be9978ed3ec7f1a9b4
- https://github.com/suuuzi/Competitive-Programming
- https://github.com/tayllan/awesome-algorithms
- https://www.commonlounge.com/community/447e8e3a307a447eb922ff7a965e9d97
- https://icpc.baylor.edu/
- http://www.ahmedshamsularefin.id.au/acm-icpc/
- http://www.ioccc.org/
- http://www.pythonchallenge.com/
- http://www3.cs.stonybrook.edu/~algorith/
- https://code.tutsplus.com/tutorials/the-wordpress-settings-api-part-1-what-it-is-why-it-matters--wp-24060
- http://acm.timus.ru/
- http://acm.tju.edu.cn/toj/
- https://www.quora.com/topic/TopCoder
- https://community.topcoder.com/tc?module=ProblemArchive&sr=&er=&sc=&sd=&class=&cat=&div1l=&div2l=1&mind1s=&mind2s=&maxd1s=&maxd2s=&wr=
- https://www.topcoder.com/members/tourist/
- http://www.trythis0ne.com/
- https://github.com/turingschool/data_structures_and_algorithms
- https://www.commonlounge.com/community/6c080f4866bf489598b7883253144985
- https://codesays.com/unofficial-solutions-to-the-problems-by-leetcode/
- https://www.urionlinejudge.com.br/judge/en/login
- https://github.com/miguelarauj1o/URI/tree/master/src
- https://uva.onlinejudge.org/index.php?option=com_comprofiler
- https://www.quora.com/What-are-some-good-blogs-for-learning-algorithms-and-competitive-programming-techniques
- https://www.quora.com/What-are-some-good-resources-to-learn-C++-for-competitive-programming
- https://www.quora.com/What-are-some-of-the-best-websites-to-learn-competitive-coding
- https://www.quora.com/What-are-some-of-the-most-useful-blogs-for-competitive-programming
- https://www.quora.com/What-are-some-top-competitive-programming-blogs
- https://www.quora.com/What-are-the-best-resources-for-competitive-programming-in-Python
- https://www.quora.com/What-are-the-best-resources-for-learning-coding-for-competitive-programming-contests
- https://www.quora.com/What-does-it-take-to-go-to-the-ACM-ICPC
- https://www.quora.com/What-have-you-gained-from-competitive-programming
- https://www.quora.com/What-is-an-API-application-programming-interface-and-how-do-I-create-one
- https://www.quora.com/What-is-best-approach-for-competitive-programming
- https://www.quora.com/What-is-the-best-blog-on-competitive-programming
- https://www.quora.com/What-is-the-best-competitive-programming-reference-to-bring-to-a-competition
- https://www.quora.com/What-is-the-best-resource-to-learn-Java-for-competitive-programming
- https://www.quora.com/What-is-the-best-strategy-to-improve-my-skills-in-competitive-programming-in-2-3-months
- https://www.quora.com/What-is-the-best-way-to-become-a-software-developer-in-the-developing-world
- https://www.quora.com/What-is-the-best-way-to-prepare-for-ACM-ICPC-2016-17
- http://androidadvices.com/why-and-how-to-downgrade-from-marshmallow-6-0-to-lollipop-5-1-1-guide/
- https://web.archive.org/web/20080913154125/http://www.comp.nus.edu.sg:80/~stevenha/programming/acmoj.html
- https://github.com/xtaci/algorithms
- https://www.hackerearth.com/sprints/redislabs-hackathon-global/
- http://qa.geeksforgeeks.org/hot
- http://qa.geeksforgeeks.org/questions
- http://petr-mitrichev.blogspot.com/search?updated-min=2016-01-01T00:00:00%2B03:00&updated-max=2017-01-01T00:00:00%2B03:00&max-results=41
- https://www.hackerearth.com/practice/codemonk/
- https://www.topcoder.com/community/data-science/data-science-tutorials/
- http://e-maxx-eng.appspot.com/
- http://wcipeg.com/wiki/Special:AllPages
- https://github.com/jaehyunp/stanfordacm
- https://visualgo.net/
- https://www.hackerrank.com/calendar
- http://www.cs.princeton.edu/~wayne/kleinberg-tardos/
- https://atcoder.jp/
- https://atcoder.jp/contest
- https://github.com/sindresorhus/awesome
- http://codeforces.me/blog/entry/3273
- https://www3.ntu.edu.sg/home/ehchua/programming/howto/CodeBlocks_HowTo.html
- https://www3.ntu.edu.sg/home/ehchua/programming/howto/Cygwin_HowTo.html#mingw
- http://www.havenondemand.com/
- https://dev.havenondemand.com/apis
- http://www.commonlounge.com/discussion/a0a6977f9b8d45399afcad2d01193398
- http://www.spoj.com/problems/classical/sort=6
- http://www.cs.colostate.edu/~anderson/cs200/index.html/doku.php?id=useful_links
- http://www.cs.colostate.edu/~anderson/cs200/index.html/doku.php?id=recit:array_based_queue
- https://www.youtube.com/geeksforgeeksvideos
- http://codeforces.me/blog/entry/8387
- https://github.com/stjepang/snippets
- http://codeforces.me/blog/entry/44190
- http://poj.org/userstatus?user_id=harrypotter0
- http://codeforces.me/gyms/
- https://arena.topcoder.com/#/u/dashboard
- http://mr-johal.com/get/476740/pledge-of-allegiance-prod-by-ty-james-lloyd-banks.html
- https://groups.google.com/forum/#!myforums
- http://r.recruit-jinji.jp/code_fes/us/index.html
- http://code-festival-2016-qualc.contest.atcoder.jp/
- http://codeforces.me/blog/entry/47901
- https://atcoder.jp/contest?categories=&mode=button
- http://usaco.org/index.php?page=contests
- https://www.techgig.com/practice
- http://usaco.org/index.php?page=viewproblem2&cpid=641
- https://www.hackerearth.com/practice/
- https://discuss.codechef.com/questions/?sort=mostvoted
- https://blog.codechef.com/
- https://www.codechef.com/getting-started
- http://www.spoj.com/contests/
- http://www.iarcs.org.in/inoi/
- http://www.iarcs.org.in/inoi/online-study-material/index.php
- http://cpptruths.blogspot.in/
- http://www.infopulse.com/blog/timsort-sorting-algorithm/
- https://codingforspeed.com/
- https://helloacm.com/
- http://codeforces.me/blog/entry/16221
- http://codeforces.me/blog/entry/15729
- http://codeforces.me/blog/entry/13529
- http://codeforces.me/blog/entry/15890
- http://codeforces.me/blog/entry/13520
- http://codeforces.me/blog/entry/3781
- http://codeforces.me/blog/entry/10355
- http://codeforces.me/blog/entry/619
- http://codeforces.me/blog/entry/1492
- http://codeforces.me/blog/entry/18455
- https://www.quora.com/Dynamic-Programming-DP/Are-there-any-good-resources-or-tutorials-for-dynamic-programming-besides-the-TopCoder-tutorial
- https://www.quora.com/Are-there-any-good-tutorial-blogs-on-Codeforces
- https://discuss.codechef.com/questions/48877/data-structures-and-algorithms
- http://codeforces.me/blog/entry/43286
- http://codeforces.me/blog/entry/8008
- https://www.quora.com/Which-are-the-top-blogs-to-follow-to-explore-about-algorithms-and-data-structures
- https://www.codechef.com/wiki/tutorials
- https://discuss.codechef.com/
- https://www.quora.com/Who-are-the-best-coders-to-follow-on-GitHub https://www.quora.com/Who-are-the-best-coders-to-follow-on-GitHub http://codeforces.me/blog/entry/43230 https://www.quora.com/Who-are-some-of-the-programmers-on-GitHub-to-learn-from https://github.com/aalhour/C-Sharp-Algorithms https://github.com/absnaik810/SPOJ-Repository https://www.quora.com/topic/ACM-International-Collegiate-Programming-Contest-ICPC http://www.geeksforgeeks.org/tag/acm-icpc/ https://contest.yandex.com/algorithm2015/ https://handong1587.github.io/algorithm_and_data_structure/2015/07/01/resourses.html https://www.quora.com/topic/Algorithms http://petr-mitrichev.blogspot.in/2009/10/gennady-korotkevich.html http://eulercoder.me/AlgoWiki/ http://codeforces.me/blog/entry/23054 https://github.com/ashim888/dataStructureAndAlgorithm http://codeforces.me/blog/entry/43578?locale=en https://discuss.codechef.com/questions/64426/awesome-resource-for-ds-and-algorithms https://www.commonlounge.com/discussion/97e9927870d84b51a7dc5d4a52d5434d/main http://shivamkhandelwal.in/beginners-guide-to-competitive-programming/ https://github.com/bnmnetp/pythonds http://codeluli.blogspot.in/ https://www.quora.com/topic/Competitive-Programming https://machlearner.wordpress.com/resources/ https://www.quora.com/Competitive-Programming-How-do-I-practice-smartly https://www.quora.com/Competitive-Programming-What-is-the-best-way-to-progress-through-practice-problems-on-CodeChef-SPOJ-TopCoder-etc https://github.com/Michael0x2a/curated-programming-resources/blob/master/resources.md https://github.com/esbanarango/Competitive-Programming https://github.com/EvgenyKarkan/EKAlgorithms https://gist.github.com/sharmaeklavya2/5299a4cd059a6f6f8699 https://github.com/haoel/leetcode https://www.quora.com/How-can-I-improve-in-competitive-programming https://github.com/haseebr/competitive-programming http://www.geeksforgeeks.org/how-to-prepare-for-acm-icpc/ https://www.quora.com/Im-preparing-for-the-ACM-ICPC-2016-what-should-be-the-perfect-strategy-and-how-much-time-should-I-practice-daily https://www.hackerearth.com/practice/notes/iterative-tree-traversals/ http://blog.hackerearth.com/2013/09/competitive-programming-getting-started_11.html https://github.com/miguelarauj1o/URI http://codeforces.me/blog/entry/16245 http://codeforces.me/blog/entry/10480 https://www.hackerearth.com/practice/notes/trending/ https://github.com/marioyc/Online-Judge-Solutions/tree/master/Timus%20Online%20Judge https://github.com/palcu/algo https://github.com/phishman3579/java-algorithms-implementation https://github.com/prakhar1989/Algorithms https://github.com/prakharcode/Algo_Ds_Notes http://codeforces.me/blog/entry/11437 https://github.com/ramswaroop/Algorithms-and-Data-Structures-in-Java http://psyho.gg/ https://github.com/raywenderlich/swift-algorithm-club https://github.com/rodrigoalvesvieira/competitive-programming https://discuss.leetcode.com/topic/30746/share-some-analysis-and-explanations https://github.com/tayllan/awesome-algorithms https://github.com/turingschool/data_structures_and_algorithms https://www.quora.com/What-are-the-best-resources-for-learning-coding-for-competitive-programming-contests https://www.quora.com/What-are-some-good-resources-to-learn-C++-for-competitive-programming https://www.quora.com/What-are-some-of-the-best-websites-to-learn-competitive-coding https://www.quora.com/What-are-some-of-the-most-useful-blogs-for-competitive-programming https://www.quora.com/What-are-some-good-blogs-for-learning-algorithms-and-competitive-programming-techniques?redirected_qid=2912752https://www.quora.com/What-is-best-approach-for-competitive-programming https://www.quora.com/What-are-some-good-blogs-for-learning-algorithms-and-competitive-programming-techniques?redirected_qid=4637165 https://www.quora.com/What-is-the-best-competitive-programming-reference-to-bring-to-a-competition https://www.quora.com/What-is-the-best-resource-to-learn-Java-for-competitive-programming https://www.quora.com/What-is-the-best-strategy-to-improve-my-skills-in-competitive-programming-in-2-3-months https://www.hackerearth.com/practice/codemonk/
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- Hope you will find them useful and feel free to recommend other links/resources useful in competitive programming :)