榪欐槸鎻忚堪涓縐嶇畻娉曢渶瑕佸灝?#8220;鏃墮棿”鐨勫害閲忋傦紙涔熸湁絀洪棿澶嶆潅鎬э紝浣嗗洜涓哄畠浠兘鐩鎬簰杞崲錛屾墍浠ラ氬父鎴戜滑灝辮鏃墮棿澶嶆潅鎬с傚浜庡ぇ灝忎負(fù) n 鐨勮緭鍏ワ紝鎴戜滑鐢ㄥ惈 n 鐨勭畝鍖栧紡瀛愭潵琛ㄨ揪銆傦紙鎵璋撶畝鍖栧紡瀛愶紝灝辨槸蹇界暐緋繪暟銆佸父鏁幫紝浠呬繚鐣欐渶“澶?#8221;鐨勯偅閮ㄥ垎錛?
姣斿鎵懼嚭 n 涓暟涓渶澶х殑涓涓紝寰堢畝鍗曪紝灝辨槸鎶婄涓涓暟鍜岀浜屼釜姣旓紝鍏朵腑澶х殑閭ｄ釜鍐嶅拰絎笁涓瘮錛屼緷嬈＄被鎺紝鎬誨叡瑕佹瘮 n-1 嬈★紝鎴戜滑璁頒綔 O(n) (瀵逛簬 n 鍙互鏄緢澶у緢澶х殑鎯呭喌涓嬶紝-1鍙互蹇界暐涓嶈浜嗭級(jí)銆?
鍐嶆瘮濡備粠灝忓埌澶ф帓濂界殑 n 涓暟錛屼粠涓壘鍑虹瓑浜?x 鐨勯偅涓備竴縐嶆柟娉曟槸鎸夌潃欏哄簭浠庡ご鍒板熬涓涓釜鎵撅紝鏈濂芥儏鍐墊槸絎竴涓氨鏄?x錛屾渶鍧忔儏鍐墊槸姣旇緝浜?n 嬈＄洿鏈鍚庝竴涓紝鍥犳鏈鍧忔儏鍐典笅鐨勮綆楀鏉傚害涔熸槸 O(n)銆傝繕鏈変竴縐嶆柟娉曪細(xì)鍏堝彇涓棿閭ｄ釜鏁板拰 x 姣旇緝錛屽鍋忓ぇ鍒欏湪鍓嶄竴鍗婃暟涓壘錛屽鍋忓皬鍒欏湪鍚庝竴鍗婃暟涓壘錛屾瘡嬈￠兘鏄彇涓棿鐨勯偅涓暟榪涜姣旇緝錛屽垯鏈鍧忔儏鍐墊槸 lg(n)/lg2銆傚拷鐣ョ郴鏁發(fā)g2錛岀畻娉曞鏉傚害鏄疧(lgn)銆?
##璁＄畻澶嶆潅鎬х殑鎺掑簭錛?
鏍規(guī)嵁鍚?n 鐨勮〃杈懼紡闅?n 澧炲ぇ鐨勫闀塊熷害錛屽彲浠ュ皢瀹冧滑鎺掑簭錛? < lg(n) < n < nlg(n) < n^2 < ... < n^k (k鏄父鏁幫級(jí)< ... < 2^n銆傛渶鍚庤繖涓?2 鐨?n 嬈℃柟灝辨槸綰ф暟澧為暱浜嗭紝璇昏繃媯嬬洏涓婃斁楹︾矑鏁呬簨鐨勪漢閮界煡閬撹繖涓闀塊熷害鏈夊蹇傝屼箣鍓嶇殑閭ｄ簺閮芥槸 n 鐨勫欏瑰紡鏃墮棿鐨勫鏉傚害銆備負(fù)浠涔堟垜浠湪榪欓噷蹇界暐鎵鏈夌殑緋繪暟銆佸父鏁幫紝渚嬪 2*n^3+9*n^2 鍙互琚畝鍖栦負(fù) n^3錛熺敤闆嗗悎浠涔堢殑閮借兘瑙ｉ噴錛屾垜蹇樹簡綺劇‘鐨勮娉曚簡銆傚鏋滀綘榪樿寰楀井縐垎鐨勮瘽灝辨兂鍍忎竴涓嬪 (2*n^3+9*n^2)/(n^3) 姹傚錛岀粨鏋滄槸0錛屾病鍖哄埆錛屽涓嶏紵
##P 闂錛氬涓涓棶棰橈紝鍑℃槸鑳芥壘鍒拌綆楀鏉傚害鍙互琛ㄧず涓哄欏瑰紡鐨勭‘瀹氱畻娉曪紝榪欎釜闂灝卞睘浜?P (polynomial) 闂銆?
##NP 闂錛?
NP 涓殑 N 鏄寚闈炵‘瀹氱殑(non-deterministic錛夌畻娉曪紝榪欐槸榪欐牱涓縐嶇畻娉曪細(xì)錛?錛夌寽涓涓瓟妗堛傦紙2錛夐獙璇佽繖涓瓟妗堟槸鍚︽紜傦紙3錛夊彧瑕佸瓨鍦ㄦ煇嬈￠獙璇侊紝絳旀鏄紜殑錛屽垯璇ョ畻娉曞緱瑙ｃ?
NP (non-deterministic polynomial)闂灝辨槸鎸囷紝鐢ㄨ繖鏍風(fēng)殑闈炵‘瀹氱殑綆楁硶錛岄獙璇佹楠わ紙2錛夋湁澶氶」寮忔椂闂寸殑璁＄畻澶嶆潅搴︾殑綆楁硶銆?
##闂鐨勫綊綰︼細(xì)
榪?#8230;…鎴戣鐢ㄤ粈涔堟湳璇潵瑙ｉ噴鍛紵闆嗗悎錛熷お闅捐娓呬簡……濡傛灉浣犺繕璁板緱鍑芥暟鐨勬槧灝勭殑璇濆氨姣旇緝瀹規(guī)槗鎯寵薄浜嗐?
澶ц嚧灝辨槸榪欐牱錛氭壘浠庨棶棰?鐨勬墍鏈夎緭鍏ュ埌闂2鐨勬墍鏈夎緭鍏ョ殑瀵瑰簲錛屽鏋滅浉搴旂殑錛屼篃鑳芥湁闂2鐨勬墍鏈夎緭鍑哄埌闂1鐨勬墍鏈夎緭鍑虹殑瀵瑰簲錛屽垯鑻ユ垜浠壘鍒頒簡闂2鐨勮В娉曪紝灝辮兘閫氳繃杈撳叆銆佽緭鍑虹殑瀵瑰簲鍏崇郴錛屽緱鍒伴棶棰?鐨勮В娉曘傜敱姝ゆ垜浠闂1鍙綊綰﹀埌闂2銆?
##NP-Hard錛?
鏈夎繖鏍蜂竴縐嶉棶棰橈紝鎵鏈?NP 闂閮藉彲浠ュ綊綰﹀埌榪欑闂錛屾垜浠О涔嬩負(fù) NP-hard 闂銆?
##NP瀹屽叏闂 (NP-Complete)錛?
濡傛灉涓涓棶棰樻棦鏄?NP 闂鍙堟槸 NP-Hard 闂錛屽垯瀹冩槸 NP-Complete 闂銆傚彲婊¤凍鎬ч棶棰樺氨鏄竴涓?NP 瀹屽叏闂錛屾澶栬憲鍚嶇殑緇欏浘鏌撹壊銆佸搱瀵嗗皵欏跨幆銆佽儗鍖呫佽揣閮庨棶棰橀兘鏄?NP 瀹屽叏闂銆?
浠庣洿瑙変笂璇達(dá)紝P<=NP<=NP-Complete<=NP-Hard錛岄棶棰樼殑闅懼害閫掑銆備絾鐩墠鍙兘璇佹槑 P 灞炰簬 NP錛岀┒绔?P=NP 榪樻槸 P 鐪熷寘鍚簬 NP 榪樻湭鐭ャ?
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In computer science, bleeding edge is a term that refers to technology that is so new (and thus, presumably, not perfected) that the user is required to risk reductions in stability and productivity in order to use it. It also refers to the tendency of the latest technology to be extremely expensive. The term was first coined by Peter Barus, a Superbase programmer.
鍦ㄨ綆楁満棰嗗煙錛孊leeding Edge鎸囦竴縐嶆渶鏂扮殑銆佸洜鑰屼篃騫墮潪瀹岀編鐨勬妧鏈備嬌鐢ㄨ呬負(fù)浜嗗畠鐨勬柊錛屽氨瑕佹嬁紼沖畾鎬у拰浜ч噺鏉ュ啋闄┿傚畠涔熸寚褰撲粖鎶鏈殑姣忎竴姝ュ彂灞曢兘瓚婃潵瓚婃槀璐電殑瓚嬪娍銆傝繖涓瘝鐨勫彂鏄庤呮槸涓涓秴綰ф暟鎹簱鐨勭▼搴忓憳Peter Barus銆?/span>
The term is formed as an allusion to "leading edge" and its synonym cutting edge, but implying a greater degree of risk: the "bleeding edge" is in front of the "cutting edge". A technology may be considered bleeding edge under the following conditions:
榪欎釜璇嶏紝鍙互瑙嗕綔Leading Edge鐨勫彟涓縐嶈娉曪紝Cutting Edge鐨勫悓涔夎瘝錛屼絾鏄疊leeding Edge鏇磋闅愬惈涓縐嶉闄╃殑鍚箟錛氬拰Cutting Edge鐩告瘮錛孊leeding Edge鏇磋鍓嶅崼涓浜涖傞氬父錛屼竴縐嶆妧鏈鏋滆琚О浣滄槸Bleeding Edge錛岄偅涔堝畠閫氬父浼?xì)绗﹀悎浠ヤ笅鍑牽U嶇壒鎬ф弿榪幫細(xì)
- Lack of consensus — competing ways of doing some new thing exist and no one really knows for certain which way the market is going to go.
- 娌℃湁鍏——鍦ㄨ揪鍒板悓涓鐩爣鐨勪笉鍚岀殑鎶鏈亾璺箣涓紝娌℃湁浜虹煡閬擄紝絀剁珶鍝竴鏉¤礬浼?xì)鎴愪负甯傚満鐨勬渶緇堥夋嫨銆?/span>
- Lack of knowledge — organizations are trying to implement a new technology or product that the trade journals have not even started talking about yet, either for or against.
- 緙轟箯璁よ瘑——褰撲竴浜涙満鏋勫紑濮嬪涓欏規(guī)柊鎶鏈垨鑰呮柊浜у搧榪涜鐮斿彂鐨勬椂鍊欙紝琛屼笟濯掍綋鐢氳嚦榪樻病鏈夊紑濮嬪姝ゅ睍寮璁ㄨ錛屾棤璁烘槸璧炴垚錛岃繕鏄弽瀵廣?/span>
- Industry resistance to change — trade journals and industry leaders have spoken against a new technology or product but some organizations are trying to implement it anyway because they are convinced it is technically superior.
- 閬埌浜т笟鎶靛埗——琛屼笟濯掍綋鍜屼駭涓氱晫宸茬粡瀵規(guī)煇欏規(guī)柊鎶鏈垨鑰呮柊浜у搧榪涜鎶ㄥ嚮錛屼絾鏄竴浜涚粍緇囧拰鏈烘瀯鍥犱負(fù)鍧氫俊鍏舵妧鏈笂鐨勪紭瓚婃ц岀戶緇姫鍔涘畬鍠勪箣銆?/span>
The rewards for successful early adoption of new technologies can be great; unfortunately, the penalties for "betting on the wrong horse" or choosing the wrong product are equally large. Whenever an organization decides to take a chance on bleeding edge technology there is a good chance that they will be stuck with a white elephant or worse.
鏈鏃╂垚鍔熼噰鐢ㄦ柊鎶鏈墍甯︽潵鐨勫洖鎶ュ彲鑳戒細(xì)闈炲父涓板帤錛涚劧鑰岋紝濡傛灉浣犱笅娉ㄤ笅閿欎簡錛屼綘閬埌鐨勬儵緗氫細(xì)鍚屾牱鍙銆傚洜姝わ紝褰撲竴涓粍緇囧喅瀹氶噰鐢˙leeding Edge鐨勬柊鎶鏈椂錛屼粬浠湁鍙兘鍥犳鑰岃儗涓婃矇閲嶇殑璐熸媴鐢氳嚦鏇寸碂銆?/span>
Recently however, the term bleeding edge has been increasingly used by the general public to mean "ahead of cutting edge" largely without the negative, risk-associated connotation concurrent with the term's use in more specific fields.
浣嗘槸鐜板湪錛屽湪瓚婃潵瓚婂鐨勬櫘閬嶇敤娉曚腑錛孊leeding Edge宸茬粡鎴愪負(fù)涓涓彧鏄己璋冨墠鍗ц屾病鏈夐闄╂х殑璇嶈銆?/span>
An apt quotation concerning this issue is:"But when you're living on the bleeding edge, you should not be surprised when you do, infact, bleed."
涓涓紩鐢ㄧ幆澧冩槸錛?#8220;褰撲綘閫夋嫨浜咮leeding Edge鐨勬妧鏈箣鍚庯紝浣犲氨涓嶅簲璇ヤ負(fù)姝や粯鍑虹殑浠ｄ環(huán)鑰屾劅鍒伴渿鎯娿?#8221;
Bleeding
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1錛夊湪C涓?/span>struct鏄敤鏉ュ皝瑁呮暟鎹殑錛屽叾涓笉鑳藉鏈夊嚱鏁版垚鍛橈紝鍙橀噺榛樿鐨勫瓨鍙栨潈闄愭槸public鐨勶紱
2錛夎屽湪C++涓泦鎴愪簡鍦?/span>C涓殑鐢ㄦ硶騫跺仛鍑烘敼榪涳紝閭ｅ氨鏄厑璁?/span>struct涓湁鎴愬憳鍑芥暟錛岃繖綰補(bǔ)鏄負(fù)浜嗗拰C鍏煎錛屽洜姝ゅ鏋滀笉闇瑕佸拰C鍏煎鎴栦紶閫掑弬鏁扮粰C錛屽緩璁湪C++涓笉鐢?/span>struct錛?/span>
鑰屽疄闄呬腑錛屽ぇ澶氭暟紼嬪簭鍛樹範(fàn)鎯敤struct瀹氫箟鍙惈鏁版嵁鎴愬憳鐨勭粨鏋勶紝鑰岀敤class瀹氫箟鏃㈠惈鏁版嵁鎴愬憳涔熸睏鍑芥暟鎴愬憳鐨勭粨鏋勶紱
3錛夊湪C++涓袱鑰呮湁寰皬鐨勭敤娉曞樊寮傦細(xì)涓鏄?/span>class涓垚鍛橀粯璁ょ殑瀛樺彇鏉冮檺鏄?/span>private鐨勶紝鑰?/span>struct涓垚鍛橀粯璁ゆ槸public鐨勶紱浜屾槸鍦ㄧ敤妯℃澘鐨勬椂鍊欏彧鑳藉啓鎴?/span>template <class Type>鎴?/span>template <typename Type>錛岃屼笉鑳藉啓鎴?/span><struct Type>錛?/span>
4錛夊彟澶栵紝鍙互榪欐牱璇翠笉綆″畾涔夊湪鍩虹被榪樻槸媧劇敓綾伙紝class鐨?/span>data member 鍜?nbsp;闈?/span>virtual function鐨勫瓨鍙栨晥鐜囧拰struct鏄竴鏍風(fēng)殑錛堟垨璇村鏋滄病鏈夊鎬佸拰铏氭嫙緇ф壙錛屼簩鑰呭瓨鍙栨晥鐜囩浉鍚岋級(jí)錛?/span>
PS錛氬鏈変笉鎭板綋涔嬪錛屾湜璇鋒寚鏁欙紒
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鎭惰ˉ鐨勮繃紼嬩腑錛屾葷粨浜嗕竴浜涢棶棰橈紝鏈潃浜ゆ祦涓庡垎浜殑鍑哄彂鐐癸紝鍋朵細(xì)鍦ㄨ繖閲屼笉瀹氭湡鏇存柊錛屽笇鏈涘C++鍒濆鑰呮湁鎵甯姪錛佷篃璇鋒寚鍑哄伓鐨勯敊璇箣澶勶紒
PS:涓嬮潰鎻愬埌鐨勮鐐瑰茍闈炲叏閮ㄥ睘浜庤嚜宸憋紝寰堝鏄潵鑷悇鎶鏈鍧涘ぇ鐗涗箣浣滐紝鍦ㄦ寮曠敤錛岃阿榪囧厛
Question錛氱紪璇戝櫒浼?xì)鑷姩鍒涘缓閭ｄ簺鎴愬憳鍑芥暟鍛㈠Q熶粈涔堟儏鍐典笅鎴戜滑涓嶉渶瑕佽嚜宸卞啓榪欎簺鍑芥暟鍛紵錛堝鐢熼棶鏃訛紝鎴戣浜嗕笁縐嶏紝灝戜簡assignment operator錛?br>Answer錛歝onstructor(鏋勯犲嚱鏁?;destructor(鏋愭瀯鍑芥暟)錛沜opy constructor(澶嶅埗鏋勯犲嚱鏁?錛沘ssignment operator(璧嬪兼搷浣滅)
浠uman涓轟緥錛?br> Human();//榛樿鏋勯犲嚱鏁?br> ~Human();//鏋愭瀯鍑芥暟
Human(const Human& p);//澶嶅埗鏋勯犲嚱鏁?br> Human & operator = (const Human & lvalue);//璧嬪兼搷浣滅鍑芥暟
瀛︾敓鍙堥棶浜嗘棦鐒剁紪璇戝櫒緇欐垜浠嚜鍔ㄥ垱寤轟簡榪欎簺鏋勯犲嚱鏁幫紝涓轟粈涔堟垜浠繕瑕侀噸鏂拌嚜宸卞畾涔夊憿錛?br> 鏅曞掞紝鎴戦棶“鏋勯犲嚱鏁扮殑浣滅敤鏄粈涔堝憿錛?#8221; 絳旀洶“鍒濆鍖栨暟鎹垚鍛橈紙鍥犱負(fù)鏃犳硶鍦ㄧ被閲岄潰緇欐垚鍛樺彉閲忚祴鍒濆鹼級(jí)” “浠呬粎濡傛鍚楋紝濡傛灉闇瑕佸疄鐜頒竴浜涘姛鑳藉憿錛岃涓嶈鍦ㄦ瀯閫犲嚱鏁伴噷鍐欙紵鍥炵瓟鏄偗瀹氱殑”銆傝嚦浜庡叾浠栧嚑涓瀯閫犲嚱鏁板埆鏈夌敤閫旓紝鍙﹁璁ㄨ錛?br> 瀛︾敓娌℃湁紺哄急鐨勬剰鎬濓紝鍙嶉棶閬?#8220;閭ｄ粈涔堟儏鍐典笅錛屾垜浠笉闇瑕佸啓榪欎簺鍑芥暟鍛?#8221;
紼嶇◢鑰冭檻浜嗕竴涓嬶紝“濡傛灉娌℃湁鍐欐瀯閫犲嚱鏁幫紝緙栬瘧鍣ㄤ細(xì)鑷姩鐢熸垚涓涓笉甯﹀弬鏁扮殑鏋勯犲嚱鏁板嵆榛樿鏋勯犲嚱鏁幫紝鏋愭瀯鍑芥暟綾諱技”錛屾殏鏃舵暦琛嶄簡涓涓嬨傚悗鏉ュ張鎯籌紝鑷充簬澶嶅埗鏋勯犲嚱鏁板拰璧嬪煎憿錛熸煡浜嗕竴涓嬫墠鐭ラ亾錛氬鏋滄垜浠彧鐢ㄥ熀鏈暟鎹被鍨嬶紝鑰屾病鏈夌敤鎸囬拡鎴栬呭紩鐢ㄤ綔涓烘暟鎹垚鍛橈紝姝ゆ椂灝變笉闇瑕佽嚜宸卞啓榪欎簺鍑芥暟銆傛墍浠ヤ竴鑸儏鍐典笅錛屾垜浠氬父閮藉啓涓婅繖鍑犱釜鏋勯犲嚱鏁幫紒
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