文章目录
- 算法的运行时间T(n)
- 关于输入规模的函数f(n)
- 常用的三种记号:
- Θ(渐进紧确界)
- theorem:(
- O记号:
- Ω记号:
- 等式和不等式中的渐进记号
- o记号:
-
记号
算法的运行时间T(n)
关于输入规模的函数f(n)
常用的三种记号:
Θ(渐进紧确界)
对于这里g(n)往往是一个简单的式子(比如n,n^2 等)
而f(n)往往会较g(n)来的长一些,比如an^2+bn+c
theorem:(%3C%2Ftitle%3E%0A%3Cdefs%20aria-hidden%3D%22true%22%3E%0A%3Cpath%20stroke-width%3D%221%22%20id%3D%22E1-MJMAIN-398%22%20d%3D%22M56%20340Q56%20423%2086%20494T164%20610T270%20680T388%20705Q521%20705%20621%20601T722%20341Q722%20260%20693%20191T617%2075T510%204T388%20-22T267%203T160%2074T85%20189T56%20340ZM610%20339Q610%20428%20590%20495T535%20598T463%20651T384%20668Q332%20668%20289%20638T221%20566Q168%20485%20168%20339Q168%20274%20176%20235Q189%20158%20228%20105T324%2028Q356%2016%20388%2016Q415%2016%20442%2024T501%2054T555%20111T594%20205T610%20339ZM223%20263V422H263V388H514V422H554V263H514V297H263V263H223Z%22%3E%3C%2Fpath%3E%0A%3Cpath%20stroke-width%3D%221%22%20id%3D%22E1-MJMAIN-2C%22%20d%3D%22M78%2035T78%2060T94%20103T137%20121Q165%20121%20187%2096T210%208Q210%20-27%20201%20-60T180%20-117T154%20-158T130%20-185T117%20-194Q113%20-194%20104%20-185T95%20-172Q95%20-168%20106%20-156T131%20-126T157%20-76T173%20-3V9L172%208Q170%207%20167%206T161%203T152%201T140%200Q113%200%2096%2017Z%22%3E%3C%2Fpath%3E%0A%3Cpath%20stroke-width%3D%221%22%20id%3D%22E1-MJMATHI-4F%22%20d%3D%22M740%20435Q740%20320%20676%20213T511%2042T304%20-22Q207%20-22%20138%2035T51%20201Q50%20209%2050%20244Q50%20346%2098%20438T227%20601Q351%20704%20476%20704Q514%20704%20524%20703Q621%20689%20680%20617T740%20435ZM637%20476Q637%20565%20591%20615T476%20665Q396%20665%20322%20605Q242%20542%20200%20428T157%20216Q157%20126%20200%2073T314%2019Q404%2019%20485%2098T608%20313Q637%20408%20637%20476Z%22%3E%3C%2Fpath%3E%0A%3Cpath%20stroke-width%3D%221%22%20id%3D%22E1-MJMAIN-3A9%22%20d%3D%22M55%20454Q55%20503%2075%20546T127%20617T197%20665T272%20695T337%20704H352Q396%20704%20404%20703Q527%20687%20596%20615T666%20454Q666%20392%20635%20330T559%20200T499%2083V80H543Q589%2081%20600%2083T617%2093Q622%20102%20629%20135T636%20172L637%20177H677V175L660%2089Q645%203%20644%202V0H552H488Q461%200%20456%203T451%2020Q451%2089%20499%20235T548%20455Q548%20512%20530%20555T483%20622T424%20656T361%20668Q332%20668%20303%20658T243%20626T193%20560T174%20456Q174%20380%20222%20233T270%2020Q270%207%20263%200H77V2Q76%203%2061%2089L44%20175V177H84L85%20172Q85%20171%2088%20155T96%20119T104%2093Q109%2086%20120%2084T178%2080H222V83Q206%20132%20162%20199T87%20329T55%20454Z%22%3E%3C%2Fpath%3E%0A%3Cpath%20stroke-width%3D%221%22%20id%3D%22E1-MJMAIN-29%22%20d%3D%22M60%20749L64%20750Q69%20750%2074%20750H86L114%20726Q208%20641%20251%20514T294%20250Q294%20182%20284%20119T261%2012T224%20-76T186%20-143T145%20-194T113%20-227T90%20-246Q87%20-249%2086%20-250H74Q66%20-250%2063%20-250T58%20-247T55%20-238Q56%20-237%2066%20-225Q221%20-64%20221%20250T66%20725Q56%20737%2055%20738Q55%20746%2060%20749Z%22%3E%3C%2Fpath%3E%0A%3C%2Fdefs%3E%0A%3Cg%20stroke%3D%22currentColor%22%20fill%3D%22currentColor%22%20stroke-width%3D%220%22%20transform%3D%22matrix(1%200%200%20-1%200%200)%22%20aria-hidden%3D%22true%22%3E%0A%20%3Cuse%20xlink%3Ahref%3D%22%23E1-MJMAIN-398%22%20x%3D%220%22%20y%3D%220%22%3E%3C%2Fuse%3E%0A%20%3Cuse%20xlink%3Ahref%3D%22%23E1-MJMAIN-2C%22%20x%3D%22778%22%20y%3D%220%22%3E%3C%2Fuse%3E%0A%20%3Cuse%20xlink%3Ahref%3D%22%23E1-MJMATHI-4F%22%20x%3D%221223%22%20y%3D%220%22%3E%3C%2Fuse%3E%0A%20%3Cuse%20xlink%3Ahref%3D%22%23E1-MJMAIN-2C%22%20x%3D%221987%22%20y%3D%220%22%3E%3C%2Fuse%3E%0A%20%3Cuse%20xlink%3Ahref%3D%22%23E1-MJMAIN-3A9%22%20x%3D%222432%22%20y%3D%220%22%3E%3C%2Fuse%3E%0A%20%3Cuse%20xlink%3Ahref%3D%22%23E1-MJMAIN-29%22%20x%3D%223154%22%20y%3D%220%22%3E%3C%2Fuse%3E%0A%3C%2Fg%3E%0A%3C%2Fsvg%3E)
O记号:
由定义可见,对于例子,我们可以说
属于集合
Ω记号:
后半句话中,应把
视为函数f(n)的集合
等式和不等式中的渐进记号
o记号:
记号