浣嗘槸鏈夌殑鏃跺欎笉榪斿洖浠諱綍涓滆タ鏄笉琛岀殑闃褲?/p>
榪斿洖寮曠敤錛岃繑鍥炴寚閽堬紝榪斿洖瀵硅薄鍒板簳鎬庝箞鍐欙紵錛?br />
鈥斺斺斺斺斺斺斺斺斺斺斺斺斺斺斺斺斺斺斺斺斺斺斺斺斺斺斺斺斺?br />涓嬮潰鏄譏錛d腑鐨勫唴瀹?/p>
鎹鐖卞洜鏂潶鏇炬彁鍑鴻繃榪欐牱鐨勫緩璁細灝藉彲鑳藉湴璁╀簨鎯呯畝鍗曪紝浣嗕笉瑕佽繃浜庣畝鍗曘傚湪c++璇█涓浉浼肩殑璇存硶搴旇鏄細灝藉彲鑳藉湴浣跨▼搴忛珮鏁堬紝浣嗕笉瑕佽繃浜庨珮鏁堛?/p>
涓鏃︾▼搴忓憳鎶撲綇浜嗏滀紶鍊尖濆湪鏁堢巼涓婄殑鎶婃焺錛堝弬瑙佹潯嬈?2錛夛紝浠栦滑浼氬彉寰楀崄鍒嗘瀬绔紝鎭ㄤ笉寰楁寲鍑烘瘡涓涓殣钘忓湪紼嬪簭涓殑浼犲兼搷浣溿傚矀涓嶇煡錛屽湪浠栦滑涓嶆噲鍦拌拷姹傜函綺圭殑鈥滀紶寮曠敤鈥濈殑榪囩▼涓紝浠栦滑浼氫笉鍙伩鍏嶅湴鐘彟涓涓弗閲嶇殑閿欒錛氫紶閫掍竴涓茍涓嶅瓨鍦ㄧ殑瀵硅薄鐨勫紩鐢ㄣ傝繖灝變笉鏄ソ浜嬩簡銆?/p>
鐪嬩竴涓〃紺烘湁鐞嗘暟鐨勭被錛屽叾涓寘鍚竴涓弸鍏冨嚱鏁幫紝鐢ㄤ簬涓や釜鏈夌悊鏁扮浉涔橈細
class rational {
public:
聽 rational(int numerator = 0, int denominator = 1);
聽 ...
private:
聽 int n, d;聽聽聽聽聽聽聽聽聽聽聽聽聽 // 鍒嗗瓙鍜屽垎姣?/p>
friend
聽 const rational聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽 // 鍙傝鏉℃21錛氫負浠涔?br />聽聽聽 operator*(const rational& lhs,聽聽聽 // 榪斿洖鍊兼槸const
聽聽聽聽聽聽聽聽聽聽聽聽聽 const rational& rhs)聽聽聽聽
};
inline const rational operator*(const rational& lhs,
聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽 const rational& rhs)
{
聽 return rational(lhs.n * rhs.n, lhs.d * rhs.d);
}
寰堟槑鏄撅紝榪欎釜鐗堟湰鐨刼perator*鏄氳繃浼犲艱繑鍥炲璞$粨鏋滐紝濡傛灉涓嶅幓鑰冭檻瀵硅薄鏋勯犲拰鏋愭瀯鏃剁殑寮閿錛屼綘灝辨槸鍦ㄩ冮伩浣滀負涓涓▼搴忓憳鐨勮矗浠匯傚彟澶栦竴浠跺緢鏄庢樉鐨勪簨瀹炴槸錛岄櫎闈炵‘瀹炴湁蹇呰錛屽惁鍒欒皝閮戒笉鎰挎剰鎵挎媴榪欐牱涓涓復鏃跺璞$殑寮閿銆傞偅涔堬紝闂灝卞綊緇撲簬錛氱‘瀹炴湁蹇呰鍚楋紵
絳旀鏄紝濡傛灉鑳借繑鍥炰竴涓紩鐢紝褰撶劧灝辨病鏈夊繀瑕併備絾璇瘋浣忥紝寮曠敤鍙槸涓涓悕瀛楋紝涓涓叾瀹冩煇涓凡緇忓瓨鍦ㄧ殑瀵硅薄鐨勫悕瀛椼傛棤璁轟綍鏃剁湅鍒頒竴涓紩鐢ㄧ殑澹版槑錛屽氨瑕佺珛鍗抽棶鑷繁錛氬畠鐨勫彟涓涓悕瀛楁槸浠涔堝憿錛熷洜涓哄畠蹇呯劧榪樻湁鍙﹀涓涓粈涔堝悕瀛楋紙瑙佹潯嬈緈1錛夈傛嬁operator*鏉ヨ錛屽鏋滃嚱鏁拌榪斿洖涓涓紩鐢紝閭e畠榪斿洖鐨勫繀欏繪槸鍏跺畠鏌愪釜宸茬粡瀛樺湪鐨剅ational瀵硅薄鐨勫紩鐢紝榪欎釜瀵硅薄鍖呭惈浜嗕袱涓璞$浉涔樼殑緇撴灉銆?/p>
浣嗭紝鏈熸湜鍦ㄨ皟鐢╫perator*涔嬪墠鏈夎繖鏍蜂竴涓璞″瓨鍦ㄦ槸娌¢亾鐞嗙殑銆備篃灝辨槸璇達紝濡傛灉鏈変笅闈㈢殑浠g爜錛?/p>
rational a(1, 2);聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽 // a = 1/2
rational b(3, 5);聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽 // b = 3/5
rational c = a * b;聽聽聽聽聽聽聽聽聽聽聽聽聽 // c 涓?3/10
鏈熸湜宸茬粡瀛樺湪涓涓間負3/10鐨勬湁鐞嗘暟鏄笉鐜板疄鐨勩傚鏋渙perator* 涓瀹氳榪斿洖榪欐牱涓涓暟鐨勫紩鐢紝灝卞繀欏昏嚜宸卞垱寤鴻繖涓暟鐨勫璞°?/p>
涓涓嚱鏁板彧鑳芥湁涓ょ鏂規硶鍒涘緩涓涓柊瀵硅薄錛氬湪鍫嗘爤閲屾垨鍦ㄥ爢涓娿傚湪鍫嗘爤閲屽垱寤哄璞℃椂浼撮殢鐫涓涓眬閮ㄥ彉閲忕殑瀹氫箟錛岄噰鐢ㄨ繖縐嶆柟娉曪紝灝辮榪欐牱鍐檕perator*錛?/p>
// 鍐欐鍑芥暟鐨勭涓涓敊璇柟娉?br />inline const rational& operator*(const rational& lhs,
聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽 const rational& rhs)
{
聽 rational result(lhs.n * rhs.n, lhs.d * rhs.d);
聽 return result;
}
榪欎釜鏂規硶搴旇琚惁鍐籌紝鍥犱負鎴戜滑鐨勭洰鏍囨槸閬垮厤鏋勯犲嚱鏁拌璋冪敤錛屼絾result蹇呴』瑕佽薄鍏跺畠瀵硅薄涓鏍瘋鏋勯犮傚彟澶栵紝榪欎釜鍑芥暟榪樻湁鍙﹀涓涓洿涓ラ噸鐨勯棶棰橈紝瀹冭繑鍥炵殑鏄竴涓眬閮ㄥ璞$殑寮曠敤錛屽叧浜庤繖涓敊璇紝鏉℃31榪涜浜嗘繁鍏ョ殑璁ㄨ銆?/p>
閭d箞錛屽湪鍫嗕笂鍒涘緩涓涓璞$劧鍚庤繑鍥炲畠鐨勫紩鐢ㄥ憿錛熷熀浜庡爢鐨勫璞℃槸閫氳繃浣跨敤new浜х敓鐨勶紝鎵浠ュ簲璇ヨ繖鏍峰啓operator*錛?/p>
// 鍐欐鍑芥暟鐨勭浜屼釜閿欒鏂規硶
inline const rational& operator*(const rational& lhs,
聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽 const rational& rhs)
{
聽 rational *result =
聽聽聽 new rational(lhs.n * rhs.n, lhs.d * rhs.d);
聽 return *result;
}
棣栧厛錛屼綘榪樻槸寰楄礋鎷呮瀯閫犲嚱鏁拌皟鐢ㄧ殑寮閿錛屽洜涓簄ew鍒嗛厤鐨勫唴瀛樻槸閫氳繃璋冪敤涓涓傚綋鐨勬瀯閫犲嚱鏁版潵鍒濆鍖栫殑錛堣鏉℃5鍜宮8錛夈傚彟澶栵紝榪樻湁涓涓棶棰橈細璋佸皢璐熻矗鐢╠elete鏉ュ垹闄ゆ帀new鐢熸垚鐨勫璞″憿錛?/p>
瀹為檯涓婏紝榪欑粷瀵規槸涓涓唴瀛樻硠婕忋傚嵆浣垮彲浠ヨ鏈峯perator*鐨勮皟鐢ㄨ呭幓鍙栧嚱鏁拌繑鍥炲煎湴鍧錛岀劧鍚庣敤delete鍘誨垹闄ゅ畠錛堢粷瀵逛笉鍙兘鈥斺旀潯嬈?1灞曠ず浜嗚繖鏍風殑浠g爜浼氭槸浠涔堟牱鐨勶級錛屼絾涓浜涘鏉傜殑琛ㄨ揪寮忎細浜х敓娌℃湁鍚嶅瓧鐨勪復鏃跺鹼紝紼嬪簭鍛樻槸涓嶅彲鑳藉緱鍒扮殑銆備緥濡傦細
rational w, x, y, z;
w = x * y * z;
涓や釜瀵筼perator*鐨勮皟鐢ㄩ兘浜х敓浜嗘病鏈夊悕瀛楃殑涓存椂鍊鹼紝紼嬪簭鍛樻棤娉曠湅鍒幫紝鍥犺屾棤娉曞垹闄ゃ傦紙鍐嶆鍙傝鏉℃31錛?/p>
涔熻錛屼綘浼氭兂浣犳瘮涓鑸殑鐔娾斺旀垨涓鑸殑紼嬪簭鍛樷斺旇鑱槑錛涗篃璁革紝浣犳敞鎰忓埌鍦ㄥ爢鏍堝拰鍫嗕笂鍒涘緩瀵硅薄鐨勬柟娉曢伩鍏嶄笉浜嗗鏋勯犲嚱鏁扮殑璋冪敤錛涗篃璁革紝浣犳兂璧蜂簡鎴戜滑鏈鍒濈殑鐩爣鏄負浜嗛伩鍏嶈繖縐嶅鏋勯犲嚱鏁扮殑璋冪敤錛涗篃璁革紝浣犳湁涓姙娉曞彲浠ュ彧鐢ㄤ竴涓瀯閫犲嚱鏁版潵鎼炴巶涓鍒囷紱涔熻錛屼綘鐨勭溂鍓嶅嚭鐜頒簡榪欐牱涓孌典唬鐮侊細operator*榪斿洖涓涓滃湪鍑芥暟鍐呴儴瀹氫箟鐨勯潤鎬乺ational瀵硅薄鈥濈殑寮曠敤錛?/p>
// 鍐欐鍑芥暟鐨勭涓変釜閿欒鏂規硶
inline const rational& operator*(const rational& lhs,
聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽 const rational& rhs)
{
聽 static rational result;聽聽聽聽聽 // 灝嗚浣滀負寮曠敤榪斿洖鐨?br />聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽 // 闈欐佸璞?/p>
聽 lhs鍜宺hs 鐩鎬箻錛岀粨鏋滄斁榪況esult錛?/p>
聽 return result;
}
榪欎釜鏂規硶鐪嬭搗鏉ュソ璞℃湁鎴忥紝铏界劧鍦ㄥ疄闄呭疄鐜頒笂闈㈢殑浼唬鐮佹椂浣犱細鍙戠幇錛屼笉璋冪敤涓涓猺ational鏋勯犲嚱鏁版槸涓嶅彲鑳界粰鍑簉esult鐨勬紜肩殑錛岃岄伩鍏嶈繖鏍風殑璋冪敤姝f槸鎴戜滑瑕佽皥璁虹殑涓婚銆傚氨綆椾綘瀹炵幇浜嗕笂闈㈢殑浼唬鐮侊紝浣嗭紝浣犲啀鑱槑涔熶笉鑳芥渶緇堟尳鏁戣繖涓笉騫哥殑璁捐銆?/p>
鎯崇煡閬撲負浠涔堬紝鐪嬬湅涓嬮潰榪欐鍐欏緱寰堝悎鐞嗙殑鐢ㄦ埛浠g爜錛?/p>
bool operator==(const rational& lhs,聽聽聽聽聽 // rationals鐨刼perator==
聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽 const rational& rhs);聽聽聽聽 //
rational a, b, c, d;
...
if ((a * b) == (c * d)) {
聽 澶勭悊鐩哥瓑鐨勬儏鍐?
} else {
聽 澶勭悊涓嶇浉絳夌殑鎯呭喌;
}
鐪嬪嚭鏉ヤ簡鍚楋紵((a*b) == (c*d)) 浼氭案榪滀負true錛屼笉綆錛宐錛宑鍜宒鏄粈涔堝鹼紒
鐢ㄧ瓑浠風殑鍑芥暟褰㈠紡閲嶅啓涓婇潰鐨勭浉絳夊垽鏂鍙ュ氨寰堝鏄撴槑鐧藉彂鐢熻繖涓鍙伓琛屼負鐨勫師鍥犱簡錛?/p>
if (operator==(operator*(a, b), operator*(c, d)))
娉ㄦ剰褰搊perator==琚皟鐢ㄦ椂錛屾繪湁涓や釜operator*鍒氳璋冪敤錛屾瘡涓皟鐢ㄨ繑鍥瀘perator*鍐呴儴鐨勯潤鎬乺ational瀵硅薄鐨勫紩鐢ㄣ備簬鏄紝涓婇潰鐨勮鍙ュ疄闄呬笂鏄姹俹perator==瀵光渙perator*鍐呴儴鐨勯潤鎬乺ational瀵硅薄鐨勫尖濆拰鈥渙perator*鍐呴儴鐨勯潤鎬乺ational瀵硅薄鐨勫尖濊繘琛屾瘮杈冿紝榪欐牱鐨勬瘮杈冧笉鐩哥瓑鎵嶆憿錛?/p>
騫歌繍鐨勮瘽錛屾垜浠ヤ笂鐨勮鏄庡簲璇ヨ凍浠ヨ鏈嶄綘錛氭兂鈥滃湪璞perator*榪欐牱鐨勫嚱鏁伴噷榪斿洖涓涓紩鐢ㄢ濆疄闄呬笂鏄湪嫻垂鏃墮棿銆備絾鎴戞病騫肩鍒頒細鐩鎬俊騫歌繍鎬諱細鍏変復鑷繁銆備竴浜涗漢鈥斺斾綘浠煡閬撹繖浜涗漢鏄寚璋佲斺旀鍒諱細鍦ㄦ兂錛屸滃敂錛屼笂闈㈤偅涓柟娉曪紝濡傛灉涓涓潤鎬佸彉閲忎笉澶熺敤錛屼篃璁稿彲浠ョ敤涓涓潤鎬佹暟緇勨︹︹?/p>
璇峰氨姝ゆ墦浣忥紒鎴戜滑闅鵑亾榪樻病鍙楀鍚楋紵
鎴戜笉鑳借鑷繁鍐欎竴孌電ず渚嬩唬鐮佹潵澶珮榪欎釜璁捐錛屽洜涓哄嵆浣垮彧鎶辨湁涓婇潰榪欑鎯蟲硶閮借凍浠ヤ護浜烘劅鍒扮緸鎰с傞鍏堬紝浣犲繀欏婚夋嫨涓涓猲錛屾寚瀹氭暟緇勭殑澶у皬銆傚鏋渘澶皬錛屽氨浼氭病鍦版柟鍌ㄥ瓨鍑芥暟榪斿洖鍊鹼紝榪欏拰鎴戜滑鍓嶉潰鍚﹀畾鐨勯偅涓滈噰鐢ㄥ崟涓潤鎬佸彉閲忕殑璁捐鈥濈浉姣旀病鏈変粈涔堟敼榪涖傚鏋渘澶ぇ錛屽氨浼氶檷浣庣▼搴忕殑鎬ц兘錛屽洜涓哄嚱鏁扮涓嬈¤璋冪敤鏃舵暟緇勪腑姣忎釜瀵硅薄閮借琚垱寤恒傝繖浼氬甫鏉涓瀯閫犲嚱鏁板拰n涓瀽鏋勫嚱鏁扮殑寮閿錛屽嵆浣胯繖涓嚱鏁板彧琚皟鐢ㄤ竴嬈°傚鏋滆"optimization"錛堟渶浼樺寲錛夋槸鎸囨彁楂樿蔣浠剁殑鎬ц兘鐨勮繃紼嬶紝 閭d箞鐜板湪榪欑鍋氭硶綆鐩村彲浠ョО涓?pessimization"錛堟渶宸寲錛夈傛渶鍚庯紝鎯蟲兂鎬庝箞鎶婇渶瑕佺殑鍊兼斁鍒版暟緇勭殑瀵硅薄涓互鍙婇渶瑕佸澶х殑寮閿錛熷湪瀵硅薄闂翠紶鍊肩殑鏈鐩存帴鐨勬柟娉曟槸閫氳繃璧嬪鹼紝浣嗚祴鍊肩殑寮閿鍙堟湁澶氬ぇ鍛紵涓鑸潵璇達紝瀹冪浉褰撲簬璋冪敤涓涓瀽鏋勫嚱鏁幫紙鎽ф瘉鏃у鹼級鍐嶅姞涓婅皟鐢ㄤ竴涓瀯閫犲嚱鏁幫紙鎷瘋礉鏂板鹼級銆備絾鎴戜滑鐜板湪鐨勭洰鏍囨鏄負浜嗛伩鍏嶆瀯閫犲拰鏋愭瀯鐨勫紑閿鍟婏紒闈㈠鐜板疄鍚э細榪欎釜鏂規硶涔熺粷瀵逛笉鑳介夌敤銆?/p>
鎵浠ワ紝鍐欎竴涓繀欏昏繑鍥炰竴涓柊瀵硅薄鐨勫嚱鏁扮殑姝g‘鏂規硶灝辨槸璁╄繖涓嚱鏁拌繑鍥炰竴涓柊瀵硅薄銆傚浜巖ational鐨刼perator*鏉ヨ錛岃繖鎰忓懗鐫瑕佷笉灝辨槸涓嬮潰鐨勪唬鐮侊紙灝辨槸鏈鍒濈湅鍒扮殑閭f浠g爜錛夛紝瑕佷笉灝辨槸鏈川涓婂拰瀹冪瓑浠風殑浠g爜錛?/p>
inline const rational operator*(const rational& lhs,
聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽聽 const rational& rhs)
{
聽 return rational(lhs.n * rhs.n, lhs.d * rhs.d);
}
鐨勭‘錛岃繖浼氬鑷粹渙perator*鐨勮繑鍥炲兼瀯閫犲拰鏋愭瀯鏃跺甫鏉ョ殑寮閿鈥濓紝浣嗗綊鏍圭粨搴曞畠鍙槸鐢ㄥ皬鐨勪唬浠鋒崲鏉ユ紜殑紼嬪簭榪愯琛屼負鑰屽凡銆傚喌涓旓紝浣犳墍鎷呭績鐨勫紑閿榪樻湁鍙兘姘歌繙涓嶄細鍑虹幇錛氬拰鎵鏈夌▼搴忚璁¤璦涓鏍鳳紝c++鍏佽緙栬瘧鍣ㄧ殑璁捐鑰呴噰鐢ㄤ竴浜涗紭鍖栨帾鏂芥潵鎻愰珮鎵鐢熸垚鐨勪唬鐮佺殑鎬ц兘錛屾墍浠ワ紝鍦ㄦ湁浜涘満鍚堬紝operator*鐨勮繑鍥炲間細琚畨鍏ㄥ湴闄ゅ幓錛堣鏉℃m20錛夈傚綋緙栬瘧鍣ㄩ噰鐢ㄤ簡榪欑浼樺寲鏃訛紙褰撳墠澶ч儴鍒嗙紪璇戝櫒榪欎箞鍋氾級錛岀▼搴忓拰浠ュ墠涓鏍風戶緇伐浣滐紝鍙笉榪囨槸榪愯閫熷害姣斾綘棰勮鐨勮蹇屽凡銆?/p>
浠ヤ笂璁ㄨ鍙互褰掔粨涓猴細褰撻渶瑕佸湪榪斿洖寮曠敤鍜岃繑鍥炲璞¢棿鍋氬喅瀹氭椂錛屼綘鐨勮亴璐f槸閫夋嫨鍙互瀹屾垚姝g‘鍔熻兘鐨勯偅涓傝嚦浜庢庝箞璁╄繖涓夋嫨鎵浜х敓鐨勪唬浠峰敖鍙兘鐨勫皬錛岄偅鏄紪璇戝櫒鐨勭敓浜у晢鍘繪兂鐨勪簨銆?/p>