{"id":16247188,"url":"https://github.com/dotnetcarpenter/dynamic_programming","last_synced_at":"2025-04-08T11:49:33.021Z","repository":{"id":66935937,"uuid":"472773219","full_name":"dotnetCarpenter/dynamic_programming","owner":"dotnetCarpenter","description":"Watching youtu.be/oBt53YbR9Kk and scrible down some code along the way","archived":false,"fork":false,"pushed_at":"2022-03-22T13:11:45.000Z","size":4,"stargazers_count":0,"open_issues_count":0,"forks_count":0,"subscribers_count":1,"default_branch":"main","last_synced_at":"2025-02-14T08:12:30.671Z","etag":null,"topics":[],"latest_commit_sha":null,"homepage":null,"language":"JavaScript","has_issues":true,"has_wiki":null,"has_pages":null,"mirror_url":null,"source_name":null,"license":null,"status":null,"scm":"git","pull_requests_enabled":true,"icon_url":"https://github.com/dotnetCarpenter.png","metadata":{"files":{"readme":"README.md","changelog":null,"contributing":null,"funding":null,"license":null,"code_of_conduct":null,"threat_model":null,"audit":null,"citation":null,"codeowners":null,"security":null,"support":null,"governance":null,"roadmap":null,"authors":null,"dei":null,"publiccode":null,"codemeta":null}},"created_at":"2022-03-22T13:11:30.000Z","updated_at":"2022-03-22T13:11:50.000Z","dependencies_parsed_at":"2023-06-30T04:00:56.658Z","dependency_job_id":null,"html_url":"https://github.com/dotnetCarpenter/dynamic_programming","commit_stats":{"total_commits":2,"total_committers":1,"mean_commits":2.0,"dds":0.0,"last_synced_commit":"98fa1d9e8cd40b620408e7e686ea2a2dcca3179e"},"previous_names":[],"tags_count":0,"template":false,"template_full_name":null,"repository_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/dotnetCarpenter%2Fdynamic_programming","tags_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/dotnetCarpenter%2Fdynamic_programming/tags","releases_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/dotnetCarpenter%2Fdynamic_programming/releases","manifests_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories/dotnetCarpenter%2Fdynamic_programming/manifests","owner_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners/dotnetCarpenter","download_url":"https://codeload.github.com/dotnetCarpenter/dynamic_programming/tar.gz/refs/heads/main","host":{"name":"GitHub","url":"https://github.com","kind":"github","repositories_count":247838415,"owners_count":21004576,"icon_url":"https://github.com/github.png","version":null,"created_at":"2022-05-30T11:31:42.601Z","updated_at":"2022-07-04T15:15:14.044Z","host_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub","repositories_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repositories","repository_names_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/repository_names","owners_url":"https://repos.ecosyste.ms/api/v1/hosts/GitHub/owners"}},"keywords":[],"created_at":"2024-10-10T14:36:14.126Z","updated_at":"2025-04-08T11:49:32.962Z","avatar_url":"https://github.com/dotnetCarpenter.png","language":"JavaScript","funding_links":[],"categories":[],"sub_categories":[],"readme":"# Dynamic Programming\n\nLearn to Solve Algorithmic Problems \u0026 Coding Challenges:\nhttps://youtu.be/oBt53YbR9Kk\n\n## fibonacci\n\nThe recursive fibonacci code can be written like this:\n\n```js\nlet fib = n =\u003e (\n n \u003c 3\n ? 1\n : fib (n - 1) + fib (n - 2)\n)\n````\n\n```\nfib (7) -\u003e 13\n```\n\n```mermaid\ngraph TB\n\nfibL025((7))\nfibL025 --- fibL1l15((6))\nfibL025 --- fibL1r24((5))\n fibL1l15 --- fibL2l09((5))\n fibL1l15 --- fibL2r14((4))\n fibL2l09 --- fibL3l05((4))\n fibL2l09 --- fibL3r08((3))\n fibL3l05 --- fibL4l03((3))\n fibL3l05 --- fibL4r04((2))\n fibL4l03 --- fibL5l01((2))\n fibL4l03 --- fibL5r02((1))\n fibL3r08 --- fibL4l06((2))\n fibL3r08 --- fibL4r07((1))\n fibL2r14 --- fibL3l12((3))\n fibL2r14 --- fibL3r13((2))\n fibL3l12 --- fibL4l10((2))\n fibL3l12 --- fibL4r11((1))\n fibL1r24 --- fibL2l20((4))\n fibL1r24 --- fibL2r23((3))\n fibL2l20 --- fibL3l18((3))\n fibL2l20 --- fibL3r19((2))\n fibL3l18 --- fibL4l16((2))\n fibL3l18 --- fibL4r17((1))\n fibL2r23 --- fibL3l21((2))\n fibL2r23 --- fibL3r22((1))\n```\n\n```\nO(2ⁿ) time\nO(n) space\n```\n\n### memorization fibonacci\n\n```js\nlet fib2 = (n, memo = {}) =\u003e {\n if (n in memo) return memo[n];\n if (n \u003c= 2) return 1;\n\n memo[n] = fib2 (n - 1, memo) + fib2 (n - 2, memo);\n return memo[n];\n}\n```\n\n```\nfib (8) -\u003e 21\n```\n\n```mermaid\ngraph TB\nfib2((8))\n\nfib2 --- fib27l((7))\n fib27l --- fib26l((6))\n fib26l --- fib25l((5))\n fib25l --- fib24l((4))\n fib24l --- fib23l((3))\n fib23l --- fib22l((2))\nfib2 --- fib26r((6))\n fib27l --- fib25r((5))\n fib26l --- fib24r((4))\n fib25l --- fib23r((3))\n fib24l --- fib22r((2))\n fib23l --- fib21r((1))\n```\n\n```\nO(n) time\nO(n) space\n```\n\nA generic memoization function that can decorate a monadic\nfunction, that is a function that takes one argument, can be\nwritten like so:\n\n```js\nlet memo = (f, o = {}) =\u003e (\n a =\u003e (\n a in o\n ? o[a]\n : (o[a] = f (a), o[a])\n )\n)\n```\n\nUsed to re-write `fib` looks like this:\n\n```js\nfib = memo (fib)\n```\n\n```\nfib (8) -\u003e 21\n```\n\n```mermaid\ngraph TB\nfib((8))\n\nfib --- 1rec1((7))\n 1rec1 --- 2rec1((6))\n 2rec1 --- 3rec1((5))\n 3rec1 --- 4rec1((4))\n 4rec1 --- 5rec1((3))\n 5rec1 --- 6rec1((2))\n 5rec1 --- 6rec2((1))\n\nfib --- 1rec2((6))\n```\n","project_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fdotnetcarpenter%2Fdynamic_programming","html_url":"https://awesome.ecosyste.ms/projects/github.com%2Fdotnetcarpenter%2Fdynamic_programming","lists_url":"https://awesome.ecosyste.ms/api/v1/projects/github.com%2Fdotnetcarpenter%2Fdynamic_programming/lists"}