鏁版嵁緇撴瀯絎簲绔犵畻娉曡璁￠[7]_璺ㄨ€冪綉

1. 緇欏畾nxm鐭╅樀A[a..b,c..d],騫惰A[i,j]鈮?/span>A[i,j+1](a鈮?/span>i鈮?/span>b,c鈮?/span>j鈮?/span>d-1)鍜?/span>A[i,j]鈮?/span>A[i+1,j](a鈮?/span>i鈮?/span>b-1,c鈮?/span>j鈮?/span>d).璁捐涓€綆楁硶鍒ゅ畾X鐨勫€兼槸鍚﹀湪A涓?/span>,瑕佹眰鏃墮棿澶嶆潅搴︿負(fù)O(m+n)銆傘€?a target="_blank">涓滃崡澶у2001鍏?/span>(13鍒?/span>)銆?/span>

銆€銆€綾諱技鏈鐨勫彟澶栧彊榪版湁錛?/span>

銆€銆€錛?/span>1錛夌粰瀹氭暣鍨嬫暟緇?/span>B[0..m,0..n] 銆傚凡鐭?/span>B涓暟鎹湪姣忎竴緇存柟鍚戜笂閮芥寜浠庡皬鍒板ぇ鐨勬搴忔帓鍒楋紝涓旀暣鍨嬪彉閲?/span>x鍦?/span>B涓瓨鍦ㄣ€傝瘯璁捐涓€涓▼搴忔鎵懼嚭涓€瀵規(guī)弧瓚?/span>B[i,j]=x鐨?/span>(i,j)鍊鹼紝瑕佹眰姣旇緝嬈℃暟涓嶈秴榪?/span>m+n.銆傘€?a target="_blank">娓呭崕澶у 1998 鍏紙10鍒嗭級銆?/span>

銆€銆€(2) 緇欏畾n脳m鐭╅樀A[a..b,c..d]錛屽茍璁?/span>A[i,j]<=A[i,j+1]錛?/span>a<=i<=b,c<=j<=d-1錛夌煡A[i,j]<=A[i+1,j],(a<=i<=b-1, c<=j<=d)銆傝璁′竴綆楁硶浠ユ瘮O(n*m)灝忕殑鏈€鍧忔椂闂村鏉傛€у垽瀹氬€?/span>x鏄惁鍦?/span>A涓€傘€?a target="_blank" class="keylink">涓滃崡澶у1994涓?/span>(17鍒?/span>)銆?/span>

銆€銆€銆愬弬鑰冪瓟妗堛€?/span>

銆€銆€[棰樼洰鍒嗘瀽]鐭╅樀涓厓绱犳寜琛屽拰鎸夊垪閮藉凡鎺掑簭錛岃姹傛煡鎵炬椂闂村鏉傚害涓?/span>O錛?/span>m+n錛夛紝鍥犳涓嶈兘閲囩敤甯歌鐨勪簩灞傚驚鐜殑鏌ユ壘銆傚彲浠ュ厛浠庡彸涓婅錛?/span>i=a,j=d錛夊厓绱犱笌x姣旇緝錛屽彧鏈変笁縐嶆儏鍐碉細(xì)涓€鏄?/span>A[i,j]>x錛?/span> 榪欐儏鍐典笅鍚?/span>j 灝忕殑鏂瑰悜緇х畫鏌ユ壘錛涗簩鏄?/span>A[i,j]<x錛屼笅姝ュ簲鍚?/span>i澶х殑鏂瑰悜鏌ユ壘錛涗笁鏄?/span>A[i,j]=x錛屾煡鎵炬垚鍔熴€傚惁鍒欙紝鑻ヤ笅鏍囧凡瓚呭嚭鑼冨洿錛屽垯鏌ユ壘澶辮觸銆?/span>

銆€銆€void search(datatype A[ ][ ], int a,b,c,d, datatype x)

銆€銆€//n*m鐭╅樀A,琛屼笅鏍囦粠a鍒?/span>b,鍒椾笅鏍囦粠c鍒?/span>d,鏈畻娉曟煡鎵?/span>x鏄惁鍦ㄧ煩闃?/span>A涓?/span>.

銆€銆€{i=a; j=d; flag=0; //flag鏄垚鍔熸煡鍒?/span>x鐨勬爣蹇?/span>

銆€銆€while(i<=b && j>=c)

銆€銆€if(A[i][j]==x) {flag=1;break;}

銆€銆€else if (A[i][j]>x) j--; else i++;

銆€銆€if(flag) printf(鈥?/span>A[%d][%d]=%d鈥?/span>,i,j,x); //鍋囧畾x涓烘暣鍨?/span>.

銆€銆€else printf(鈥滅煩闃?/span>A涓棤%d 鍏冪礌鈥濓紝x)錛?/span>

銆€銆€}綆楁硶search緇撴潫銆?/span>

銆€銆€[綆楁硶璁ㄨ]綆楁硶涓煡鎵?/span>x鐨勮礬綰夸粠鍙充笂瑙掑紑濮嬶紝鍚戜笅錛堝綋x>A[i,j]錛夋垨鍚戝乏錛堝綋x<A[i,j]錛夈€傚悜涓嬫渶澶氭槸m錛屽悜宸︽渶澶氭槸n銆傛渶浣蟲儏鍐墊槸鍦ㄥ彸涓婅姣旇緝涓€嬈℃垚鍔燂紝鏈€宸槸鍦ㄥ乏涓嬭錛?/span>A[b,c]錛夛紝姣旇緝m+n嬈★紝鏁呯畻娉曟渶宸椂闂村鏉傚害鏄?/span>O(m+n錛夈€?/span>