V\u00ec tr\u00ean hai b\u00e0n tay c\u00f3 10 ng\u00f3n tay m\u00e0 lo\u00e0i ng\u01b0\u1eddi \u0111\u00e3 ph\u00e1t minh ra h\u1ec7 \u0111\u1ebfm th\u1eadp ph\u00e2n. M\u00e1y t\u00ednh \u0111i\u1ec7n t\u1eed r\u00f5 r\u00e0ng kh\u00f4ng c\u00f3 m\u1ed1i li\u00ean h\u1ec7 t\u1ef1 nhi\u00ean v\u1edbi h\u1ec7 \u0111\u1ebfm th\u1eadp ph\u00e2n v\u00ec v\u1ec1 m\u1eb7t l\u00ed lu\u1eadn c\u0169ng nh\u01b0 \u1ee9ng d\u1ee5ng th\u1eadt kh\u00f3 c\u00f3 m\u1ed1i li\u00ean h\u1ec7 tr\u1ef1c ti\u1ebfp, li\u00ean th\u00f4ng v\u1edbi h\u1ec7 \u0111\u1ebfm th\u1eadp ph\u00e2n. Nh\u01b0ng t\u1ea1i sao m\u00e1y t\u00ednh \u0111i\u1ec7n t\u1eed v\u00e0 h\u1ec7 \u0111\u1ebfm th\u1eadp ph\u00e2n kh\u00f4ng c\u00f3 m\u1ed1i li\u00ean h\u1ec7 t\u1ef1 nhi\u00ean? M\u1ed1i quan h\u1ec7 t\u1ef1 nhi\u00ean gi\u1eefa m\u00e1y t\u00ednh v\u00e0 c\u00e1ch ghi s\u1ed1 l\u00e0 \u1edf ch\u1ed7 n\u00e0o?<\/p>\n\n\n\n
\u0110\u1ec3 gi\u1ea3i \u0111\u00e1p c\u00e2u h\u1ecfi n\u00e0y ta ph\u1ea3i xu\u1ea5t ph\u00e1t t\u1eeb nguy\u00ean l\u00ed ho\u1ea1t \u0111\u1ed9ng c\u1ee7a m\u00e1y t\u00ednh. M\u00e1y t\u00ednh \u0111i\u1ec7n t\u1eed l\u00e0m vi\u1ec7c \u0111\u01b0\u1ee3c nh\u1edd c\u00f3 d\u00f2ng \u0111i\u1ec7n. X\u00e9t m\u1ed9t ti\u1ebfp \u0111i\u1ec3m trong m\u1ea1ch \u0111i\u1ec7n t\u1eed ch\u1ec9 c\u00f3 hai tr\u1ea1ng th\u00e1i li\u00ean quan \u0111\u1ebfn s\u1ef1 cho d\u00f2ng \u0111i\u1ec7n ch\u1ea1y qua m\u1ea1ch: \u0111\u00f3ng m\u1ea1ch v\u00e0 m\u1edf m\u1ea1ch. M\u00e1y t\u00ednh l\u01b0u gi\u1eef th\u00f4ng tin nh\u1edd b\u0103ng t\u1eeb ho\u1eb7c \u0111\u0129a t\u1eeb: v\u1edbi \u0111\u0129a t\u1eeb \u1edf m\u1ed7i \u0111i\u1ec3m ghi ch\u1ec9 c\u00f3 hai tr\u1ea1ng th\u00e1i: \u0111\u01b0\u1ee3c t\u1eeb ho\u00e1 v\u00e0 kh\u00f4ng \u0111\u01b0\u1ee3c t\u1eeb ho\u00e1. Trong nh\u1eefng n\u0103m g\u1ea7n \u0111\u00e2y ph\u01b0\u01a1ng ph\u00e1p ghi th\u00f4ng tin tr\u00ean \u0111\u0129a quang ng\u00e0y c\u00e0ng ph\u1ed5 bi\u1ebfn. M\u1ed7i \u0111i\u1ec3m ghi tr\u00ean \u0111\u0129a quang ch\u1ec9 c\u00f3 hai tr\u1ea1ng th\u00e1i: ho\u1eb7c l\u00f5m ho\u1eb7c l\u1ed3i c\u00f3 t\u00e1c d\u1ee5ng kh\u00e1c nhau r\u00f5 r\u1ec7t ho\u1eb7c t\u1ee5 \u00e1nh s\u00e1ng ho\u1eb7c g\u00e2y t\u00e1n x\u1ea1 \u00e1nh s\u00e1ng. Do v\u1eady c\u00f3 th\u1ec3 th\u1ea5y n\u1ebfu m\u00e1y t\u00ednh ghi nh\u1eadn th\u00f4ng tin th\u00f4ng qua c\u00e1c ph\u01b0\u01a1ng ti\u1ec7n trung gian th\u00ec \u0111\u1ec1u th\u00f4ng qua hai tr\u1ea1ng th\u00e1i c\u1ee7a c\u00e1c ph\u01b0\u01a1ng ti\u1ec7n trung gian. Ng\u01b0\u1eddi ta ch\u1ee9ng minh \u0111\u01b0\u1ee3c r\u1eb1ng n\u1ebfu d\u00f9ng m\u00e1y tinh ghi s\u1ed1 theo h\u1ec7 \u0111\u1ebfm th\u1eadp ph\u00e2n s\u1ebd g\u00e2y kh\u00e1 nhi\u1ec1u l\u00e3ng ph\u00ed. (V\u00ed nh\u01b0 \u0111\u1ec3 ghi m\u1ed9t s\u1ed1 c\u00f3 m\u1ed9t ch\u1eef s\u1ed1 theo h\u1ec7 \u0111\u1ebfm th\u1eadp ph\u00e2n \u00edt nh\u1ea5t c\u1ea7n \u0111\u1ebfn b\u1ed1n \u0111i\u1ec3m ghi – c\u00f3 th\u1ec3 \u0111\u1ebfn 16 tr\u1ea1ng th\u00e1i – v\u00e0 c\u00f3 \u0111\u1ebfn s\u00e1u tr\u1ea1ng th\u00e1i kh\u00f4ng \u0111\u01b0\u1ee3c s\u1eed d\u1ee5ng).<\/p>\n\n\n\n
Th\u1ebf th\u00ec m\u00e1y t\u00ednh \u0111i\u1ec7n t\u1eed c\u1ea7n ghi s\u1ed1 theo h\u1ec7 \u0111\u1ebfm n\u00e0o? Xu\u1ea5t ph\u00e1t t\u1eeb h\u1ec7 qu\u1ea3 m\u1ed7i ph\u01b0\u01a1ng ti\u1ec7n trung gian \u0111\u1ec1u c\u00f3 c\u00e1c \u0111i\u1ec3m ghi th\u00f4ng tin \u1ee9ng v\u1edbi hai tr\u1ea1ng th\u00e1i, n\u00ean \u0111i\u1ec1u d\u1ec5 th\u1ea5y l\u00e0 d\u00f9ng h\u1ec7 \u0111\u1ebfm nh\u1ecb ph\u00e2n s\u1ebd c\u00f3 s\u1ef1 th\u00edch h\u1ee3p t\u1ef1 nhi\u00ean.<\/p>\n\n\n\n
Trong h\u1ec7 \u0111\u1ebfm nh\u1ecb ph\u00e2n, \u0111\u1ec3 ghi c\u00e1c con s\u1ed1 ch\u1ec9 c\u1ea7n hai k\u00ed hi\u1ec7u 0 v\u00e0 1. C\u00f3 th\u1ec3 d\u00f9ng s\u1ed1 1 bi\u1ec3u di\u1ec5n cho qua d\u00f2ng \u0111i\u1ec7n v\u00e0 0 bi\u1ec3u di\u1ec5n s\u1ef1 ng\u1eaft d\u00f2ng \u0111i\u1ec7n; ho\u1eb7c 1 l\u00e0 tr\u1ea1ng th\u00e1i b\u1ecb t\u1eeb ho\u00e1 v\u00e0 0 l\u00e0 tr\u1ea1ng th\u00e1i kh\u00f4ng b\u1ecb t\u1eeb ho\u00e1; ho\u1eb7c 1 ch\u1ec9 \u0111i\u1ec3m l\u00f5m v\u00e0 0 ch\u1ec9 \u0111i\u1ec3m l\u1ed3i. T\u1eeb \u0111\u00f3 cho th\u1ea5y h\u1ec7 \u0111\u1ebfm c\u01a1 s\u1ed1 2 th\u00edch h\u1ee3p cho vi\u1ec7c ghi nh\u1eadn th\u00f4ng tin trong c\u00e1c m\u00e1y t\u00ednh khi c\u00e1c th\u00f4ng tin \u0111\u01b0\u1ee3c m\u00e3 ho\u00e1 b\u1eb1ng c\u00e1c ch\u1eef s\u1ed1. Theo ng\u00f4n ng\u1eef m\u00e1y t\u00ednh, m\u1ed9t con s\u1ed1 ghi theo h\u1ec7 \u0111\u1ebfm nh\u1ecb ph\u00e2n l\u00e0 m\u1ed9t bit, t\u00e1m bit \u0111\u01b0\u1ee3c g\u1ecdi l\u00e0 m\u1ed9t k\u00ed t\u1ef1 (byte).<\/p>\n\n\n\n
Vi\u1ec7c d\u00f9ng h\u1ec7 \u0111\u1ebfm nh\u1ecb ph\u00e2n trong m\u00e1y t\u00ednh qu\u1ea3 l\u00e0 r\u1ea5t t\u1ef1 nhi\u00ean, nh\u01b0ng \u0111\u1ee9ng v\u1ec1 ph\u01b0\u01a1ng di\u1ec7n giao l\u01b0u gi\u1eefa m\u00e1y v\u00e0 ng\u01b0\u1eddi th\u00ec c\u0169ng c\u00f3 nh\u01b0\u1ee3c \u0111i\u1ec3m quan tr\u1ecdng l\u00e0 c\u00e1c s\u1ed1 t\u1ef1 nhi\u00ean ghi theo h\u1ec7 \u0111\u1ebfm nh\u1ecb ph\u00e2n vi\u1ebft r\u1ea5t d\u00e0i. Nh\u01b0 con s\u1ed1 1000 trong h\u1ec7 \u0111\u1ebfm th\u1eadp ph\u00e2n n\u1ebfu vi\u1ebft d\u01b0\u1edbi d\u1ea1ng h\u1ec7 \u0111\u1ebfm nh\u1ecb ph\u00e2n s\u1ebd l\u00e0 11000011010100000, qu\u1ea3 l\u00e0 r\u1ea5t d\u00e0i.<\/p>\n\n\n\n
\u0110\u1ec3 gi\u1ea3i quy\u1ebft kh\u00f3 kh\u0103n n\u00e0y, trong l\u00ed thuy\u1ebft v\u1ec1 m\u00e1y t\u00ednh ng\u01b0\u1eddi ta s\u1eed d\u1ee5ng hai h\u1ec7 \u0111\u1ebfm b\u1ed5 tr\u1ee3 l\u00e0 c\u00e1c h\u1ec7 \u0111\u1ebfm c\u01a1 s\u1ed1 t\u00e1m v\u00e0 h\u1ec7 \u0111\u1ebfm c\u01a1 s\u1ed1<\/p>\n\n\n\n
Nh\u1edd \u0111\u00f3 m\u1ed9t con s\u1ed1 c\u00f3 ba ch\u1eef s\u1ed1 trong h\u1ec7 \u0111\u1ebfm c\u01a1 s\u1ed1 hai s\u1ebd l\u00e0 m\u1ed9t con s\u1ed1 c\u00f3 m\u1ed9t ch\u1eef s\u1ed1 trong h\u1ec7 \u0111\u1ebfm c\u01a1 s\u1ed1 t\u00e1m ch\u1ec9 b\u1eb1ng 1\/3 \u0111\u1ed9 d\u00e0i c\u1ee7a con s\u1ed1 vi\u1ebft theo h\u1ec7 \u0111\u1ebfm c\u01a1 s\u1ed1 hai, so v\u1edbi con s\u1ed1 vi\u1ebft theo h\u1ec7 \u0111\u1ebfm c\u01a1 s\u1ed1 t\u00e1m kh\u00f4ng kh\u00e1c m\u1ea5y so v\u1edbi con s\u1ed1 vi\u1ebft theo c\u01a1 s\u1ed1 10. V\u00ed d\u1ee5 con s\u1ed1 100.000 vi\u1ebft theo h\u1ec7 \u0111\u1ebfm c\u01a1 s\u1ed1 t\u00e1m s\u1ebd l\u00e0 303240. T\u01b0\u01a1ng t\u1ef1 m\u1ed9t con s\u1ed1 c\u00f3 m\u1ed9t ch\u1eef s\u1ed1 vi\u1ebft theo h\u1ec7 \u0111\u1ebfm c\u01a1 s\u1ed1 16 \u0111\u1ea1i di\u1ec7n cho m\u1ed9t con s\u1ed1 c\u00f3 4 ch\u1eef s\u1ed1 trong h\u1ec7 \u0111\u1ebfm c\u01a1 s\u1ed1 hai. M\u1ed9t k\u00ed t\u1ef1 t\u01b0\u01a1ng \u1ee9ng v\u1edbi m\u1ed9t con s\u1ed1 c\u00f3 hai ch\u1eef s\u1ed1 trong h\u1ec7 \u0111\u1ebfm c\u01a1 s\u1ed1 16. Trong h\u1ec7 \u0111\u1ebfm c\u01a1 s\u1ed1 16 c\u1ea7n c\u00f3 16 k\u00ed hi\u1ec7u \u0111\u1ed9c l\u1eadp. Th\u1ef1c t\u1ebf ng\u01b0\u1eddi ta d\u00f9ng ch\u1eef s\u1ed1 t\u1ef1 nhi\u00ean 1,2 2, 3, 4, 5, 6, 7, 8 v\u00e0 c\u00e1c ch\u1eef c\u00e1i A, B, C, D, E, F \u0111\u1ea1i di\u1ec7n cho c\u00e1c s\u1ed1 10, 11, 12, 13, 14, 15 (c\u00e1c ch\u1eef s\u1ed1 trong h\u1ec7 \u0111\u1ebfm th\u1eadp ph\u00e2n). Nh\u01b0 v\u1eady con s\u1ed1 100.000 \u0111\u01b0\u1ee3c vi\u1ebft l\u00e0 186A0. Vi\u1ec7c chuy\u1ec3n \u0111\u1ed5i t\u1eeb h\u1ec7 \u0111\u1ebfm nh\u1ecb ph\u00e2n sang h\u1ec7 \u0111\u1ebfm c\u01a1 s\u1ed1 t\u00e1m v\u00e0 c\u01a1 s\u1ed1 16 kh\u00e1 \u0111\u01a1n gi\u1ea3n; v\u00e0 vi\u1ec7c ph\u1ed1i h\u1ee3p s\u1eed d\u1ee5ng h\u1ec7 \u0111\u1ebfm c\u01a1 s\u1ed1 t\u00e1m v\u00e0 c\u01a1 s\u1ed1 16 s\u1ebd tr\u00e1nh \u0111\u01b0\u1ee3c phi\u1ec1n ph\u1ee9c khi vi\u1ebft nh\u1eefng con s\u1ed1 qu\u00e1 d\u00e0i trong h\u1ec7 \u0111\u1ebfm c\u01a1 s\u1ed1 hai. H\u1ec7 \u0111\u1ebfm c\u01a1 s\u1ed1 8 v\u00e0 c\u01a1 s\u1ed1 16 \u0111\u00e3 tr\u1ee3 gi\u00fap \u0111\u1eafc l\u1ef1c cho vi\u1ec7c giao l\u01b0u gi\u1eefa ng\u01b0\u1eddi v\u00e0 m\u00e1y t\u00ednh.<\/p>\n\n\n\n
T\u1eeb kho\u00e1: H\u1ec7 \u0111\u1ebfm c\u01a1 s\u1ed1 10; H\u1ec7 \u0111\u1ebfm c\u01a1 s\u1ed1 2; H\u1ec7 \u0111\u1ebfm c\u01a1 s\u1ed1 8; H\u1ec7<\/p>\n\n\n\n
<\/p>\n\n\n\n\n\n\n","protected":false},"excerpt":{"rendered":"
V\u00ec tr\u00ean hai b\u00e0n tay c\u00f3 10 ng\u00f3n tay m\u00e0 lo\u00e0i ng\u01b0\u1eddi \u0111\u00e3 ph\u00e1t minh ra h\u1ec7 \u0111\u1ebfm th\u1eadp ph\u00e2n. M\u00e1y t\u00ednh \u0111i\u1ec7n t\u1eed r\u00f5 r\u00e0ng kh\u00f4ng c\u00f3 m\u1ed1i li\u00ean h\u1ec7 t\u1ef1 nhi\u00ean v\u1edbi h\u1ec7 \u0111\u1ebfm th\u1eadp ph\u00e2n v\u00ec v\u1ec1 m\u1eb7t l\u00ed lu\u1eadn c\u0169ng nh\u01b0 \u1ee9ng d\u1ee5ng th\u1eadt kh\u00f3 c\u00f3 m\u1ed1i li\u00ean h\u1ec7 tr\u1ef1c ti\u1ebfp, […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":"","_disable_autopaging":false},"categories":[15,9],"tags":[],"class_list":["post-7483","post","type-post","status-publish","format-standard","hentry","category-hoi-dap-khoa-hoc","category-toan-hoc"],"_links":{"self":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/7483","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/comments?post=7483"}],"version-history":[{"count":0,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/posts\/7483\/revisions"}],"wp:attachment":[{"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/media?parent=7483"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/categories?post=7483"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.vietlearn.org\/kien-thuc\/wp-json\/wp\/v2\/tags?post=7483"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}