棣栧厛寰楀弽鐪佷笅鎴戠殑姣旇禌鎬佸害,瀵逛簬榪欎袱鍦烘瘮璧?鎴戝彲浠ヨ娌℃湁鐢ㄥ績(jī)鍋?涓昏鏈変笅闈㈠嚑鐐?
涓.鐪嬮涓嶇粏蹇?鎴栬呰鏍規(guī)湰灝辨病鐪嬭繃棰?鎬繪槸鎯寵闃熷弸鐪嬮,鐒跺悗鑷繁鎯蟲濊礬,榪欎竴鐐瑰緢涓嶅ソ,榪欎竴棰樺氨鍙互
鐪嬪嚭鏉?濡傛灉褰撴椂鎴戜粩緇嗙湅棰樼殑璇?鎴栬灝辮兘鍑轟簡(jiǎn),灝辯畻鎴戜笉鑳藉嚭,鎴栬鍜岄槦鍙嬬殑璁ㄨ涓氨鑳藉嚭鏉?鍚庢潵瀵艱嚧
闃熷弸涓鐩翠竴涓漢鍦ㄦ悶榪欎釜棰?鎴戜竴鐩村湪閰辨補(bǔ) – -||,榪欓噷鍚戜袱浣嶉槦鍙嬭〃紺哄涓嶈搗.榪樻湁灝辨槸榪樻病鐪嬮灝變細(xì)鏈?/p>
鐐規(guī)亹鎯ф劅,鎬繪曡嚜宸變笉鑳藉仛鍑烘潵,榪欏氨鏄績(jī)鎬佺殑闂浜?鎴戞兂涓嬩竴鍦哄紑濮嬫垜浼?xì)璋冨ソ鑷忿q殑蹇?jī)鎬佺殑銆?br>浜?涓嶈兘闈?rùn)涓嬪績(jī)鏉ヤ粩缁嗘兂棰?榪欎竴鐐歸潪甯鎬笉濂?鎰熻榪欎袱鍦烘瘮璧涜嚜宸卞仛鐨勫緢嫻簛,寰堜笉濂?鍙互璇存病鏈夊叡鐚?
榪欏嚑澶╁ソ濂藉弽鎬濅笅鑷繁,鍦ㄤ笅涓鍦烘瘮璧涗簤鍙栧仛鐨勫緢濂藉惂銆傚姞娌癸紒錛侊紒
涓嬮潰璇磋榪欓鐨勬濊礬
瀵逛簬閭ｄ釜ERROR At point x寰堝ソ鍥炵瓟,鍙渶瑕佷竴涓猙ool鏁扮粍灝卞彲浠ヨВ鍐充簡(jiǎn).鍓╀笅鐨勫氨鏄浜岄棶浜?鍏跺疄榪欏彲
浠ョ湅鎴愭槸Floyd鐨勫彉浣?瀵逛簬Floyd綆楁硶,涓鍏辨槸3閲嶅驚鐜?鏈澶栭潰閭ｄ竴灞傛槸涓棿鑺傜偣,鍦ㄨ繖閲屽彧涓嶈繃鎶婇偅涓灞?/p>
鎷嗗紑浜?jiǎn)鑰屽凡,涔熷氨鏄浜庢瘡涓涓猰arked鐨勭偣,鎶婅繖涓偣浣滀負(fù)涓棿鑺傜偣,鐒跺悗鏇存柊鎵鏈夌偣瀵圭殑鏈鐭礬(榪欓噷涓嶇敤
綆¤繖涓や釜鐐規(guī)槸鍚﹁marked,鍥犱負(fù)濡傛灉娌℃湁琚玬arked鐨勮瘽,鍚庨潰鍒ゆ柇鐨勬椂鍊欐牴鏈氨涓嶄細(xì)鐢ㄥ埌榪欎袱鐐圭殑璺濈)榪?/p>
鏍風(fēng)殑璇?灝辯浉褰撲簬鎶奆loyd鐨勬渶澶栧眰鎷嗘垚浜?jiǎn)涓涓竴涓殑鐐?榪欐牱鏃墮棿澶嶆潅搴︽槸涓嶅彉鐨?涔熷氨鏄疧(V^3)鐨?瀵逛簬
V<=300,瀹屽叏OK.涓嶈繃濂藉儚瀵逛簬姣忎釜琚玬arked鐨勭偣榪涜鎵鏈夌偣瀵圭殑鏇存柊鏃跺彲浠ュ湪澶栧眰寰幆閭ｅ姞涓垽鏂?浣嗘槸
鎴戞病鎯蟲槑鐧芥槸浠涔堛?/p>
榪欓鏄竴涓綉緇滄祦鐨勫叆闂ㄩ,鐢變簬鐐瑰拰杈歸兘涓嶅,鎵浠ュ彲浠ョ洿鎺ョ敤Edmond-Karp綆楁硶瑙ｅ喅銆傚彟澶朒DU3549涔熷彲浠ョ敤EK綆楁硶鐩存帴榪囨帀
瀵逛簬Edmond-Karp綆楁硶灝辨槸姣忔鐢╞fs鎵懼騫胯礬寰?鐒跺悗鏀瑰彉鐩稿簲鐨勬畫鐣欑綉緇滃氨ok浜?涓嶈繃榪欓瑕佹敞鎰忕殑灝辨槸涓や釜鐐逛箣闂翠笉涓瀹氬彧鏈変竴鏉¤竟,鎵浠ヨ鎶婃墍鏈夎竟閮藉姞璧鋒潵鎵嶈銆傝繖閲岃創(chuàng)涓涓嬪叧閿唬鐮?
int bfs(int s,int t,int total)
{//榪欓噷s鏄搗鐐?t鏄粓鐐?total鏄葷殑欏剁偣鏁?/span>
int front,rear,u,v;
int q[206*206];//闃熷垪 鍙互涓嶇敤寮榪欎箞澶?
memset(pre,-1,sizeof(pre));
front = rear = -1;
rear++;
q[rear] = s;
while(front < rear)
{//bfs鎵懼騫胯礬寰?/span>
front++;
u = q[front];
for(v = 1;v <= total;v++)
{
if(-1 == pre[v] && num[u][v] > 0)
{
pre[v] = u;
rear++;
q[rear] = v;
if(v == t)//濡傛灉鎵懼埌浜?jiǎn)姹囩偣灏辩洿鎺ユ帹鍑?/span>
return 1;
}
}
}
return 0;
}
void work()
{
int u,v,inc,maxflow;
maxflow = 0;//鍒濆鍖栨祦閲忎負(fù)0
while(1)
{
if(!bfs(1,m,m))//濡傛灉涓嶅瓨鍦ㄥ騫胯礬寰?涔熷氨鏄褰撳墠嫻侀噺涓烘渶澶ф祦浜?/span>
{
break;
}
inc = 99999999;
for(v = m;v != 1;v = u)
{//鎵捐繖鏉″騫胯礬寰勮兘澧炲姞鐨勬渶灝忔祦閲?/span>
u = pre[v];
if(num[u][v] < inc)
inc = num[u][v];
}
for(v = m;v != 1;v = u)
{//鏀瑰彉孌嬬暀緗戠粶
u = pre[v];
num[u][v] -= inc; //榪欐潯杈圭殑嫻侀噺鍑忓皯inc
num[v][u] += inc; //鍙嶅悜杈圭殑嫻侀噺澧炲姞inc
}
maxflow += inc;//澧炲姞緗戠粶嫻佺殑鍊?/span>
}
printf("%d\n",maxflow);
}
]]>
涓閬撳緢瑁哥殑嬈ф媺璺緞棰樸傚熀鏈笂鍙鐭ラ亾嬈ф媺璺緞鐨勭畻娉曞氨鍙互榪囩殑銆傝屼笖欏剁偣鍜岃竟鏁頒篃涓嶅銆傜洿鎺ョ煩闃靛瓨灝眔k浜?jiǎn)銆?br>瀵逛簬嬈ф媺璺緞鐨勭畻娉曪紝璇風(fēng)湅榪?/a>(鑻辨枃鐨?鏈潵鏄綉欏電殑,涓嶈繃CPP璇翠笉鑳戒紶閭ｇ鏍煎紡鐨?鍑戝悎鐫鐪嬪惂)
鏈変竴鐐瑰氨鏄敞鎰忛噸杈圭殑鎯呭喌,涔熷氨鏄瓨杈瑰拰鍒犺竟鏃朵笉鑳藉崟綰殑緗負(fù)1鍜岀疆涓?錛岃屽簲璇ユ槸鐢?+鍜?-鏉ヤ唬鏇?涓嶇劧閲嶈竟涓嶅ソ澶勭悊銆?br>榪欓噷涓婁紶浜?jiǎn)娆ф媺璧\寰勭殑閭ｄ釜HTML緗戦〉
]]>
涓寮濮嬫垜鎯崇敤Floyd鍘繪按姘達(dá)紝鍙戠幇姘翠笉榪?絎?緇?.8S錛岀8緇勬暟鎹?.56S銆備簬鏄兂鐫鐢╯pfa鍘繪悶銆?br>鍙戠幇spfa鍘熸潵榪欎釜濂藉啓,涓嶈繃涓棿鐢變簬澶ч敊涓涓笅鏍囧鑷翠簡(jiǎn)1h鐨勬?zhèn)插墽銆傘傘傝嚦浜巗pfa鐨勪粙緇嶅氨涓嶅繀鎴戞潵璇翠簡(jiǎn)鍚э紝緗戜笂涓鎼滀竴澶ф妸銆?br>鐢╯pfa鎼炲嚭鏉ョ殑鏈鍚庝竴緇勬暟鎹敤鏃?.19S銆傝繕榪囧緱鍘伙紝涓嶈繃緗戜笂鏈変漢璇寸敤spfa榪樺彲浠ヤ紭鍖栵紝灝辨槸鏍規(guī)嵁宸茬粡綆楀嚭鏉ョ殑鏈鐭礬鏉ヤ紭鍖栬繕娌＄畻鍑虹殑鏈鐭礬錛屽叿浣撳疄鐜版垜涓嶆槸寰堟噦錛?a >緇欎釜閾炬帴錛屾湁鍏磋叮鐨勭湅鐪嬨?榪欎釜閾炬帴閲岃繕鏈夊嚑縐嶆渶鐭礬鐨勭畻娉曟晥鐜囩殑姣旇緝)
榪樻湁灝辨槸鍙互鐢╤eap+dij,涓嶈繃榪欎釜heap鏈濂借繕鏄嚜宸辨墜鍐欙紝鎯沖伔鎳掔敤stl鐨勪笢瑗挎湁鏃舵槸瑕佷互鏃墮棿涓轟唬浠風(fēng)殑銆傛湁鏃剁敤stl鐨勪紭鍏堥槦鍒楁潵鎼炵殑璇濅細(xì)瓚呮椂錛屼絾鏄嚜宸辨墜鍐欏爢鐨勮瘽錛屽彲鑳戒細(xì)姣旇緝鐞嗘兂銆傛爣縐扮粰鐨勫氨鏄痟eap+dij.鍏蜂綋瀹炵幇nocow涓婂簲璇ユ湁錛岃繖閲屽氨涓嶈創(chuàng)浜?jiǎn)銆?
]]>