鎴戜滑閮界煡閬撳揩閫熸帓搴忔湁寰堝ソ鐨?/font>O(nlogn)錛岄偅涔堟洿蹇殑蹇熸帓搴忓湪鍝噷鍛紵涓嬮潰鏄垜鐨勫涔犺褰曘?/font>
錛嶏紞By JonsenElizee 2010/09/23
甯歌鐨勫揩閫熸帓搴?/font>
瀛︿範蹇熸帓搴忥紝鏈璁╀漢鐔熸倝鐨勬槸涓や釜ptr宸﹀彸鏉ュ洖鎸囷紝涓嬈℃帓搴忓悗灝辨妸涓涓?/font>mid鍊兼斁鍦ㄤ簡鍚堥傜殑浣嶇疆涓娿傝繖鏄垜涓涓湅鍙嬬殑闈為掑綊鐨?/font>C錛嬶紜瀹炵幇銆傛垜鏀瑰啓涓鐐圭偣錛屽氨鏄姞浜?/font>C鐨?/font>rand()鏉ヨ緗暟緇勫鹼紝鐒跺悗緙栬瘧榪愯榪欎釜綆楁硶錛屼綘鍙兘榪樹笉鑳介殢闅忎究渚跨殑鍐欏嚭榪欎釜綆楁硶錛屼絾鏁堟灉鐪熺殑寰堜笉涔愯錛屼篃涓嶇煡閬撹榪愯澶氫箙鎵嶈兘鎺掑簭瀹?6*50鐨勫瓧絎︿覆銆傚悗闈㈡垜浠細鐪嬪埌涓涓緢綺炬倣鐨勭畻娉曘傘傘?/font>
1 #include <stack>
2 #include <vector>
3 #include <iostream>
4 #include <stdlib.h>
5 #include <stdio.h>
6 #include <time.h>
7
8 using namespace std;
9
10 typedef struct _record
11 {
12 int begin;
13 int end;
14 }record;
15
16 void quick_sort(int a[],int len)
17 {
18 vector<record> do_job;
19 record temp;
20 temp.begin = 0;
21 temp.end = len-1;
22 do_job.push_back(temp);
23
24 while (do_job.size() != 0) {
25 record temp = do_job.back();
26 do_job.pop_back();
27
28 int low = temp.begin;
29 int high = temp.end;
30 int key = a[low];
31 while (low < high) {
32 while(low < high && a[high] >= key) high--;
33 a[low] = a[high];
34 while(low < high && a[low] <= key) low++;
35 a[high] = a[low];
36 }
37 a[low] = key;
38
39 record temp1;
40 temp1.begin = temp.begin;
41 temp1.end = low-1;
42 if (temp1.begin < temp1.end) { do_job.push_back(temp1); }
43
44 record temp2;
45 temp2.begin = low+1;
46 temp2.end = temp.end;
47 if (temp2.begin < temp2.end) { do_job.push_back(temp2); }
48 }
49 }
50 int main()
51 {
52 int a[26*50];
53 int i = 0;
54 while(i < 26*50) a[i] = rand() % 100;
55 int count =sizeof(a) / sizeof(int);
56 quick_sort(a,count);
57 for (int i = 0; i < count; i++) cout<<a[i]<<endl;
58 return 0;
59 }
60
2 #include <vector>
3 #include <iostream>
4 #include <stdlib.h>
5 #include <stdio.h>
6 #include <time.h>
7
8 using namespace std;
9
10 typedef struct _record
11 {
12 int begin;
13 int end;
14 }record;
15
16 void quick_sort(int a[],int len)
17 {
18 vector<record> do_job;
19 record temp;
20 temp.begin = 0;
21 temp.end = len-1;
22 do_job.push_back(temp);
23
24 while (do_job.size() != 0) {
25 record temp = do_job.back();
26 do_job.pop_back();
27
28 int low = temp.begin;
29 int high = temp.end;
30 int key = a[low];
31 while (low < high) {
32 while(low < high && a[high] >= key) high--;
33 a[low] = a[high];
34 while(low < high && a[low] <= key) low++;
35 a[high] = a[low];
36 }
37 a[low] = key;
38
39 record temp1;
40 temp1.begin = temp.begin;
41 temp1.end = low-1;
42 if (temp1.begin < temp1.end) { do_job.push_back(temp1); }
43
44 record temp2;
45 temp2.begin = low+1;
46 temp2.end = temp.end;
47 if (temp2.begin < temp2.end) { do_job.push_back(temp2); }
48 }
49 }
50 int main()
51 {
52 int a[26*50];
53 int i = 0;
54 while(i < 26*50) a[i] = rand() % 100;
55 int count =sizeof(a) / sizeof(int);
56 quick_sort(a,count);
57 for (int i = 0; i < count; i++) cout<<a[i]<<endl;
58 return 0;
59 }
60
鏇寸畝鏇村揩蹇熸帓搴?/font>
榪欑蹇熸帓搴忎笉鏄渶蹇殑錛岀壒鍒槸鍩烘湰鏈夊簭鏃朵細閫鍖栧埌O(n^2)錛岀悊璁轟笂鍩轟簬姣旇緝鐨勬帓搴忎笉浼氬皬浜?/font>O(nlogn)錛屼絾榪樻槸鏈夊姞閫熺殑鍙兘銆備笅闈㈣繖涓槸銆?/font>Programming Pearls 2nd銆嬮噷闈㈢殑鏂規硶錛岃繖涓畻娉曠湡鐨勫緢綺炬倣錛岃繍琛屽畬26*50鐨勪竴涓帓搴忥紝鍙渶瑕?.09縐掞紝鎴戠殑瀹炵幇濡備笅銆?/font>
榪愯鏃舵槸緇欑殑涓涓暱搴︿負26*50鐨勪竴涓瓧絎︽暟緇勶紝瀵瑰畠榪涜鎺掑簭錛?/font>
鏇寸畝鏇村揩蹇熸帓搴忥紜錛?/font>
鐮旂┒涓婇潰綆楁硶鐨勬墽琛岃繃紼嬶紝閬靛驚澶у笀鐨勬濊礬錛屾垜鏀瑰啓浜嗙畻娉曪紝鍦ㄦ垜鐨?/font>X61錛?/font>Redhat EL5涓婅繍琛岄熷害姣斾笂闈㈢殑綆楁硶蹇簡8鍊嶏紝涔熷氨鏄繍琛屽畬26*50闀跨殑鎺掑簭錛屽彧闇瑕?.01縐掞紒鏈鍚庢垜鏄庣櫧涓涓亾鐞嗭紝瑕佹湁鎬濇兂錛岃鏈夋瘏鍔涳紝瑕佹湁瀹炶返銆傚畬紼挎椂錛屾垜鍙戠幇榪欎釜綆楁硶榪樻湁鏀硅繘鐨勪綑鍦般傜壒鍜屽ぇ瀹跺垎浜傚澶氭寚鐐廣?/font>
榪愯杈撳叆鍜?/font>quick.c涓殑涓鏍鳳細
榪愯緇撴灉瀵規瘮
甯歌鐨勯偅涓潪閫掑綊鐨勭畻娉曚粠鎴戝啓榪欎釜鏂囦歡鍒扮幇鍦紝瀹冭繕鍦ㄨ繍琛岀潃銆傘傘?/font>
絎簩涓拰絎笁涓椂闂村姣斿涓嬪浘錛?/font>
(鍔犱笉鍔犱紭鍖栵紞O3閮芥槸涓鏍風殑緇撴灉錛屽湪鎴戠殑X61涓婏紝gcc version 4.1.2 20080704 (Red Hat 4.1.2-48))
鏀硅繘鐨?/font>myquick.c鐨勮繍琛屾椂闂存槸quick.c鐨?/font>1/9銆?/font>
鏈鍚庯紝鎴戜笉寰椾笉鐢?/font>Ctrl錛?/font>C鎶婇偅涓父瑙勭殑緇?/font>KILL鎺夈?/font>
Real, User and Sys process time statistics
One of these things is not like the other. Real refers to actual elapsed time; User and Sys refer to CPU time used only by the process.
*Real is wall clock time - time from start to finish of the call. This is all elapsed time including time slices used by other processes and time the process spends blocked (for example if it is waiting for I/O to complete).
*User is the amount of CPU time spent in user-mode code (outside the kernel) within the process. This is only actual CPU time used in executing the process. Other processes and time the process spends blocked do not count towards this figure.
*Sys is the amount of CPU time spent in the kernel within the process. This means executing CPU time spent in system calls within the kernel, as opposed to library code, which is still running in user-space. Like 'user', this is only CPU time used by the process.
User+Sys will tell you how much actual CPU time your process used.
One of these things is not like the other. Real refers to actual elapsed time; User and Sys refer to CPU time used only by the process.
*Real is wall clock time - time from start to finish of the call. This is all elapsed time including time slices used by other processes and time the process spends blocked (for example if it is waiting for I/O to complete).
*User is the amount of CPU time spent in user-mode code (outside the kernel) within the process. This is only actual CPU time used in executing the process. Other processes and time the process spends blocked do not count towards this figure.
*Sys is the amount of CPU time spent in the kernel within the process. This means executing CPU time spent in system calls within the kernel, as opposed to library code, which is still running in user-space. Like 'user', this is only CPU time used by the process.
User+Sys will tell you how much actual CPU time your process used.
婧愪唬鐮?/font>
鏍稿績綆楁硶瀵規瘮鍥?/font>
quick.c婧愪唬鐮?/font>
1 #include <stdio.h>
2 #include <string.h>
3 #include <stdlib.h>
4 #include <time.h>
5
6 void quick(char* str, int low, int hig);
7 void swap(char* a, char* b);
8
9 int main()
10 {
11 char ary[] = 錛忥紡26錛?0闀跨殑瀛楃涓叉暟緇勶紝鍐呭鍙傝冧笂鍥俱?/span>
12 char* str = ary;
13 printf("calling quick
");
14 quick(str, 0, strlen(str)-1);
15 return 0;
16 }
17
18 void quick(char* str, int low, int hig) {
19 if(low >= hig) return;
20 srand(time(NULL));
21 // get a random key
22 //swap(str + low, str + low + (rand() % (hig - low + 1)));
23 int i = low, j = hig + 1, key = str[low];
24 while(1)
25 {
26 while(++i <= hig && str[i] <= key);
27 while(--j >= low && str[j] > key);
28 if(i > j) break; // no need to do swap
29 swap(str + i, str + j);
30 }
31 swap(str + low, str + i - 1); // swap key to i-1 position
32 quick(str, low, i - 2);
33 quick(str, i, hig);
34 }
35
36 void swap(char* a, char* b) {
37 if(a == b) return;
38 *a ^= *b; *b ^= *a; *a ^= *b;
39 }
40
2 #include <string.h>
3 #include <stdlib.h>
4 #include <time.h>
5
6 void quick(char* str, int low, int hig);
7 void swap(char* a, char* b);
8
9 int main()
10 {
11 char ary[] = 錛忥紡26錛?0闀跨殑瀛楃涓叉暟緇勶紝鍐呭鍙傝冧笂鍥俱?/span>
12 char* str = ary;
13 printf("calling quick
");14 quick(str, 0, strlen(str)-1);
15 return 0;
16 }
17
18 void quick(char* str, int low, int hig) {
19 if(low >= hig) return;
20 srand(time(NULL));
21 // get a random key
22 //swap(str + low, str + low + (rand() % (hig - low + 1)));
23 int i = low, j = hig + 1, key = str[low];
24 while(1)
25 {
26 while(++i <= hig && str[i] <= key);
27 while(--j >= low && str[j] > key);
28 if(i > j) break; // no need to do swap
29 swap(str + i, str + j);
30 }
31 swap(str + low, str + i - 1); // swap key to i-1 position
32 quick(str, low, i - 2);
33 quick(str, i, hig);
34 }
35
36 void swap(char* a, char* b) {
37 if(a == b) return;
38 *a ^= *b; *b ^= *a; *a ^= *b;
39 }
40
myquick.c婧愪唬鐮?/font>
1 #include <stdio.h>
2 #include <string.h>
3 #include <stdlib.h>
4 #include <time.h>
5
6 void myquick(char* str, int low, int hig);
7 void swap(char* a, char* b);
8
9 int main()
10 {
11 char ary[] = 錛忥紡26錛?0闀跨殑瀛楃涓詫紝鍚宷uick.c鐨勮緭鍏ャ?/span>
12 char* str = ary;
13 printf("calling myquick");
14 myquick(str, 0, strlen(str)-1);
15 return 0;
16 }
17
18 void myquick(char* str, int low, int hig) {
19 if(low >= hig) return;// no need to sort elements
20 // elements in the right of [m] are not sorted
21 int m = low, i = low, j = hig, key = low;
22 // skip any elements that <= [key]
23 while(i <= hig && str[i] <= str[key]) {i++; m++;}
24 // skip elements > [key]
25 while(j >= low && str[j] > str[key]) j--;
26 // initially, i==j is impossible
27 while(i <= j) {
28 // swap small one to m-position
29 if(str[i] <= str[key]) { swap(str + m++, str + i); }
30 i++;
31 }
32 swap(str + low, str + m-1);
33 myquick(str, low, m - 2);
34 myquick(str, m, hig);
35 return;
36 }
37
38 void swap(char* a, char* b) {
39 if(a == b) return;
40 *a ^= *b; *b ^= *a; *a ^= *b;
41 }
42
2 #include <string.h>
3 #include <stdlib.h>
4 #include <time.h>
5
6 void myquick(char* str, int low, int hig);
7 void swap(char* a, char* b);
8
9 int main()
10 {
11 char ary[] = 錛忥紡26錛?0闀跨殑瀛楃涓詫紝鍚宷uick.c鐨勮緭鍏ャ?/span>
12 char* str = ary;
13 printf("calling myquick
");14 myquick(str, 0, strlen(str)-1);
15 return 0;
16 }
17
18 void myquick(char* str, int low, int hig) {
19 if(low >= hig) return;// no need to sort elements
20 // elements in the right of [m] are not sorted
21 int m = low, i = low, j = hig, key = low;
22 // skip any elements that <= [key]
23 while(i <= hig && str[i] <= str[key]) {i++; m++;}
24 // skip elements > [key]
25 while(j >= low && str[j] > str[key]) j--;
26 // initially, i==j is impossible
27 while(i <= j) {
28 // swap small one to m-position
29 if(str[i] <= str[key]) { swap(str + m++, str + i); }
30 i++;
31 }
32 swap(str + low, str + m-1);
33 myquick(str, low, m - 2);
34 myquick(str, m, hig);
35 return;
36 }
37
38 void swap(char* a, char* b) {
39 if(a == b) return;
40 *a ^= *b; *b ^= *a; *a ^= *b;
41 }
42
JonsenElizee 2010-09-23 15:24 鍙戣〃璇勮
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