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