{"id":193,"date":"2010-06-29T04:51:44","date_gmt":"2010-06-29T08:51:44","guid":{"rendered":"http:\/\/hw.minilinux.net\/?p=193"},"modified":"2024-09-08T13:47:02","modified_gmt":"2024-09-08T17:47:02","slug":"193","status":"publish","type":"post","link":"https:\/\/hw.minilinux.net\/?p=193","title":{"rendered":"\u6bcf\u65e55\u9898–0629"},"content":{"rendered":"

1. Given an integer, \u770b\u8fd9\u4e2ainteger\u662f\u5426\u662f\u5bf9\u79f0\u7684(palindrome), \u5c31\u662f\u6b63\u7740\u548c\u5012\u7740\u662f\u5426\u90fd\u4e00\u6837<\/p>\n

\u8fd9\u4e2a\u6709\u70b9\u610f\u601d, \u65f6\u95f4\u590d\u6742\u5ea6O(n)(n \u662finteger\u7684\u4f4d\u6570),<\/del> \u8fd9\u4e2a\u662f\u5fc5\u987b\u7684, \u4f46\u662f\u6700\u597d\u7684\u65b9\u6cd5\u5fc5\u987b\u662f\u8981\u8ba9\u7a7a\u95f4\u590d\u6742\u5ea6\u53d8\u6210O(1).<\/del><\/p>\n

\u5206\u6790\u5f97\u4ed4\u7ec6\u70b9\u5c31\u53d1\u73b0\u6211\u4e0a\u9762\u5206\u6790\u7684\u9519\u8bef, \u5982\u679c\u4ece\u5341\u4f4d\u6570\u7684\u4f4d\u6570n\u8fd9\u4e2a\u65b9\u9762\u5206\u6790, \u6211\u4eec\u53ef\u4ee5\u53d1\u73b0while loop\u662fO(n)\u7684, \u4f46\u662f\u91cc\u9762\u7684 \u4e58\u6cd5,\u9664\u6cd5\u8fd0\u7b97\u90fd\u4e5f\u662fO(n)<\/strong>\u7684, \u6240\u4ee5\u603b\u7684\u65f6\u95f4\u590d\u6742\u5ea6\u662fO(n^2)\u7684.
\n\u81f3\u4e8e\u7a7a\u95f4\u590d\u6742\u5ea6, \u6211\u4eec\u518d\u4ece\u5341\u8fdb\u5236\u7684\u4f4d\u6570\u4e0a\u6765\u5206\u6790, \u90a3\u4e48\u4e5f\u662fO(n)\u7684.<\/p>\n

(\u53e6\u5916\u8fd9\u4e2a\u95ee\u9898\u6211\u662f\u4eceMITBBS\u4e0a\u770b\u6765\u7684\u4e00\u9053\u9762\u8bd5\u9898, \u53d1\u5e16\u7684\u4eba\u7ed9\u51fa\u4e86\u4e00\u4e2a\u65b9\u6cd5\u662f\u628a\u5341\u8fdb\u5236\u7684\u6bcf\u4e00\u4f4d\u653e\u5728\u4e00\u4e2aarray\u91cc\u9762, \u7136\u540e\u7528stack\u628a\u9006\u4f4d\u50a8\u5b58\u5728\u53e6\u4e00\u4e2aarray\u5f53\u4e2d, \u8fd9\u4e2a\u5982\u679c\u6362\u4e86\u6211\u5f53\u7136\u89c9\u5f97\u662f\u6211\u73b0\u5728\u7684\u65b9\u6cd5\u7a7a\u95f4\u590d\u6742\u5ea6\u66f4\u52a0\u7b80\u4fbf, \u4f46\u662f\u5982\u679c\u4ece\u53e6\u4e00\u4e2a\u5c42\u9762\u60f3, \u5341\u8fdb\u5236\u7684int\u672c\u8eab(\u6bcf\u4e00\u4f4d)\u4e0d\u4e5f\u662f\u76f8\u5f53\u4e8e\u653e\u5728\u4e00\u4e2aarray\u5f53\u4e2d, \u53ea\u662f\u5b83\u662f\u7531\u7f16\u7801\u7684bit pattern\u800c\u786e\u5b9a\u503c, \u6211\u8fd9\u79cd\u65b9\u6cd5\u53ea\u662f\u9488\u5bf9\u5341\u8fdb\u5236\u7684int\u7c7b\u578b\u505a\u5f97\u4f18\u5316, \u4f46\u662f\u76f8\u5bf9\u800c\u8a00\u4e4b\u524d\u90a3\u4e2a\u65b9\u6cd5\u53cd\u800c\u66f4\u52a0general\u4e00\u4e9b, \u5199\u8fd9\u4e9b\u53ea\u662f\u611f\u89c9\u5206\u6790\u7a0b\u5e8f\u4f18\u7f3a\u70b9\u4ec0\u4e48\u7684\u53ef\u4ee5\u60f3\u5f97\u66f4general\u7684\u60c5\u51b5\u662f\u600e\u4e48\u6837, \u4e5f\u8bb8\u770b\u4e0a\u53bb\u5f88\u70c2\u7684\u7a0b\u5e8f\u4e5f\u6709\u81ea\u5df1\u7684\u597d\u5904, \u5c31\u50cf\u6700\u574f\u60c5\u51b5\u662fO(n^2)\u7684QuickSort\u7adf\u7136\u5728\u5b9e\u9645\u4e2d\u4f1a\u6bd4\u4e00\u76f4\u90fd\u662fO(nlogn)\u7684HeapSort\u5feb\u4e00\u6837)<\/p>\n

\u611f\u8c22\u8212\u6653\u5927\u795e\u7ed9\u51fa\u7684\u6307\u6b63!<\/p>\n

\u7ee7\u7eed\u6539\u6b63, \u5bf9\u4e8e\u7528array\u7684\u65b9\u6cd5, \u628a\u6240\u6709\u7684\u7684\u4f4d\u6570, \u653e\u5728\u4e00\u4e2aarray\u4e2d, \u7136\u540e\u7528\u524d\u540e\u4e24\u4e2a\u6307\u9488\u4e00\u4e2a\u5411\u540e,\u4e00\u4e2a\u5411\u524d,\u5c31\u662f\u5224\u65adstring\u662f\u5426\u662fpanlidrome\u7684\u65b9\u6cd5.<\/p>\n

\u53e6\u5916 \u5982\u679c\u7528\u4e0b\u9762\u7684\u65b9\u6cd5, \u6709\u53ef\u80fd\u51fa\u73b0\u7684\u95ee\u9898\u5c31\u662f\u6709\u53ef\u80fdreverse \u4e4b\u540e\u7684integer\u4f1aoverflow, \u8fd9\u4e2a\u95ee\u9898\u7684\u89e3\u51b3\u65b9\u6cd5, \u5f53\u7136\u53ef\u4ee5\u662f\u7528long long \u6765\u627f\u63a5reverse\u4e4b\u540e\u7684integer, \u4f46\u662f\u8fd9\u6837\u5c31\u663e\u5f97\u592a\u4e0dgeneral\u4e86, \u6211\u4e5f\u60f3\u8d77\u4e86atoi\u51fd\u6570\u91cc\u9762\u5f53\u65f6\u60f3\u5230\u7684\u4e00\u4e2a\u95ee\u9898, \u5982\u679coverflow\u4e86\u600e\u4e48\u529e?(\u7ee7\u7eed\u5ef6\u4f38, \u6211\u60f3\u5230\u6709\u6b21\u770b\u5230\u8ba8\u8bba\u5982\u4f55\u5224\u65adint\u7684\u4e58\u6cd5\u662f\u5426overflow\u4e86, \u6709\u4e2a\u7b80\u5355\u7684\u65b9\u6cd5\u662f\u628a\u4e58\u6cd5\u5f97\u51fa\u7684\u7ed3\u679c\u5904\u4ee5\u4efb\u4f55\u4e00\u4e2a\u4e58\u6570, \u770b\u7ed3\u679c\u662f\u4e0d\u662f\u53e6\u4e00\u4e2a\u4e58\u6570)<\/p>\n

\u8fd9\u4e2a\u662f\u5927\u5b98\u4eba\u6307\u51fa\u7684\u53ef\u80fd\u51fa\u73b0\u7684\u4e00\u4e2a\u95ee\u9898, \u611f\u8c22\u5927\u5b98\u4eba!<\/p>\n

int IsPalindrome(int m)\n{\n   int s = 0, temp = m;\n   while(temp)\n   {\n   \t\ts = s*10 + temp%10;\n   \t\ttemp = temp\/10;\n   }\n   return s==m;\n }\n<\/pre>\n
2. Array of non-negative integers. One number appears odd number of times, all the others appear even number of times. Find the number that appears odd number of times.<\/p>\n
\u770b\u5230\u8fd9\u4e2a\u9898\u76ee, \u7acb\u523b\u60f3\u5230\u4e86\u795e\u5947\u7684\u5f02\u6216(exclusive or)<\/p>\n
int FindOddnumber(int *a, int n)\n{\n   int s = 0;\n   for(int i=0; i<n; i++)\n   \t\ts ^= a[i];\n   return s;\n }\n<\/pre>\n
\u5982\u679c\u7ee7\u7eed\u95ee, \u4e0d\u80fd\u5f02\u6216\u5462, \u90a3\u4e48\u53ef\u4ee5\u8003\u8651Hashtable, \u7136\u540e\u8fdb\u4e00\u6b65\u6216\u8005Hashmap.
\nQ:
\nDifference between HashMap and HashTable?<\/p>\n
A: The HashMap class is roughly equivalent to Hashtable, except that it is unsynchronized and permits nulls. (HashMap allows null values as key and value whereas Hashtable doesnt allow). HashMap does not guarantee that the order of the map will remain constant over time. HashMap is unsynchronized and Hashtable is synchronized.<\/p>\n
3. Difference between override and overload<\/p>\n
\u4ed6\u4eec\u90fd\u662fPolymorphism\u7684\u4e00\u79cd, one name, many forms,<\/p>\n
overload \u662fcompile-time \u7684(base class, derived class)
\noverride \u662frun-time \u7684<\/p>\n
4. \u627e\u51fa\u4e00\u4e2a\u6570\u7ec4\u4e2d\u7b2cK\u5c0f\u7684\u6570(\u5047\u8bbe\u8fd9\u4e2a\u6570\u7ec4\u6ca1\u6709\u91cd\u590d)<\/p>\n
\u8fd9\u4e2a\u4e3b\u8981\u601d\u8def\u662f\u7528quicksort\u91cc\u9762\u7684partition\u51fd\u6570, \u5982\u679creturn\u503c order,
\norder = partition(int *a, int n) \u90a3\u4e48\u4ee3\u8868a[order]\u662f\u6574\u4e2a\u6570\u7ec4a\u5f53\u4e2d\u7684\u7b2corder+1\u5c0f\u7684\u6570\u5b57
\nif order+1 < K, order = partition(a+order+1, n-order-1), \u7136\u540e\u66f4\u65b0 K= K-order-1; if order+1 >K, \u7ee7\u7eed\u7528order = partition(a, order)
\nif order+1 = K, bingo, \u8fd4\u56dea[order]\u5c31\u597d\u4e86<\/p>\n
\u65f6\u95f4\u590d\u6742\u5ea6\u662fO(n), \u6700\u574f\u60c5\u51b5O(n^2), \u7136\u540e\u6709\u4e2a5\u4e2a\u70b9,5\u4e2a\u70b9\u7684,\u6392\u5217\u7684\u7b97\u6cd5, \u6700\u574f\u4e5f\u6709O(n)(\u4e0d\u8fc7\u592a\u9ebb\u70e6..)
\n\u7136\u540e\u5982\u679c\u8981\u6c42\u6570\u5217\u7684\u524dK\u5c0f\u7684\u6570, \u4e5f\u53ef\u4ee5\u7528\u7c7b\u4f3c\u8fd9\u79cd\u65b9\u6cd5, \u6216\u8005\u8fd8\u80fd\u60f3\u5230\u7684\u5c31\u662f\u7ef4\u6301\u4e00\u4e2aMax-Heap, O(nlogK)\u7684\u590d\u6742\u5ea6<\/p>\n
5. \u5b9e\u73b0 KMP \u7b97\u6cd5<\/p>\n","protected":false},"excerpt":{"rendered":"
1. Given an integer, \u770b\u8fd9\u4e2ainteger\u662f\u5426\u662f\u5bf9\u79f0\u7684(palindrome), \u5c31\u662f\u6b63\u7740\u548c\u5012\u7740\u662f\u5426\u90fd\u4e00\u6837 \u8fd9\u4e2a\u6709\u70b9\u610f\u601d, \u65f6\u95f4\u590d\u6742\u5ea6O(n)(n \u662finteger\u7684\u4f4d\u6570), \u8fd9\u4e2a\u662f\u5fc5\u987b\u7684, \u4f46\u662f\u6700\u597d\u7684\u65b9\u6cd5\u5fc5\u987b\u662f\u8981\u8ba9\u7a7a\u95f4\u590d\u6742\u5ea6\u53d8\u6210O(1). \u5206\u6790\u5f97\u4ed4\u7ec6\u70b9\u5c31\u53d1\u73b0\u6211\u4e0a\u9762\u5206\u6790\u7684\u9519\u8bef, \u5982\u679c\u4ece\u5341\u4f4d\u6570\u7684\u4f4d\u6570n\u8fd9\u4e2a\u65b9\u9762\u5206\u6790, \u6211\u4eec\u53ef\u4ee5\u53d1\u73b0while loop\u662fO(n)\u7684, \u4f46\u662f\u91cc\u9762\u7684 \u4e58\u6cd5,\u9664\u6cd5\u8fd0\u7b97\u90fd\u4e5f\u662fO(n)\u7684, \u6240\u4ee5\u603b\u7684\u65f6\u95f4\u590d\u6742\u5ea6\u662fO(n^2)\u7684. \u81f3\u4e8e\u7a7a\u95f4\u590d\u6742\u5ea6, \u6211\u4eec\u518d\u4ece\u5341\u8fdb\u5236\u7684\u4f4d\u6570\u4e0a\u6765\u5206\u6790, \u90a3\u4e48\u4e5f\u662fO(n)\u7684. (\u53e6\u5916\u8fd9\u4e2a\u95ee\u9898\u6211\u662f\u4eceMITBBS\u4e0a\u770b\u6765\u7684\u4e00\u9053\u9762\u8bd5\u9898, \u53d1\u5e16\u7684\u4eba\u7ed9\u51fa\u4e86\u4e00\u4e2a\u65b9\u6cd5\u662f\u628a\u5341\u8fdb\u5236\u7684\u6bcf\u4e00\u4f4d\u653e\u5728\u4e00\u4e2aarray\u91cc\u9762, \u7136\u540e\u7528stack\u628a\u9006\u4f4d\u50a8\u5b58\u5728\u53e6\u4e00\u4e2aarray\u5f53\u4e2d, \u8fd9\u4e2a\u5982\u679c\u6362\u4e86\u6211\u5f53\u7136\u89c9\u5f97\u662f\u6211\u73b0\u5728\u7684\u65b9\u6cd5\u7a7a\u95f4\u590d\u6742\u5ea6\u66f4\u52a0\u7b80\u4fbf, \u4f46\u662f\u5982\u679c\u4ece\u53e6\u4e00\u4e2a\u5c42\u9762\u60f3, \u5341\u8fdb\u5236\u7684int\u672c\u8eab(\u6bcf\u4e00\u4f4d)\u4e0d\u4e5f\u662f\u76f8\u5f53\u4e8e\u653e\u5728\u4e00\u4e2aarray\u5f53\u4e2d, \u53ea\u662f\u5b83\u662f\u7531\u7f16\u7801\u7684bit pattern\u800c\u786e\u5b9a\u503c, \u6211\u8fd9\u79cd\u65b9\u6cd5\u53ea\u662f\u9488\u5bf9\u5341\u8fdb\u5236\u7684int\u7c7b\u578b\u505a\u5f97\u4f18\u5316, \u4f46\u662f\u76f8\u5bf9\u800c\u8a00\u4e4b\u524d\u90a3\u4e2a\u65b9\u6cd5\u53cd\u800c\u66f4\u52a0general\u4e00\u4e9b, \u5199\u8fd9\u4e9b\u53ea\u662f\u611f\u89c9\u5206\u6790\u7a0b\u5e8f\u4f18\u7f3a\u70b9\u4ec0\u4e48\u7684\u53ef\u4ee5\u60f3\u5f97\u66f4general\u7684\u60c5\u51b5\u662f\u600e\u4e48\u6837, \u4e5f\u8bb8\u770b\u4e0a\u53bb\u5f88\u70c2\u7684\u7a0b\u5e8f\u4e5f\u6709\u81ea\u5df1\u7684\u597d\u5904, \u5c31\u50cf\u6700\u574f\u60c5\u51b5\u662fO(n^2)\u7684QuickSort\u7adf\u7136\u5728\u5b9e\u9645\u4e2d\u4f1a\u6bd4\u4e00\u76f4\u90fd\u662fO(nlogn)\u7684HeapSort\u5feb\u4e00\u6837) \u611f\u8c22\u8212\u6653\u5927\u795e\u7ed9\u51fa\u7684\u6307\u6b63! \u7ee7\u7eed\u6539\u6b63, \u5bf9\u4e8e\u7528array\u7684\u65b9\u6cd5, \u628a\u6240\u6709\u7684\u7684\u4f4d\u6570, \u653e\u5728\u4e00\u4e2aarray\u4e2d, \u7136\u540e\u7528\u524d\u540e\u4e24\u4e2a\u6307\u9488\u4e00\u4e2a\u5411\u540e,\u4e00\u4e2a\u5411\u524d,\u5c31\u662f\u5224\u65adstring\u662f\u5426\u662fpanlidrome\u7684\u65b9\u6cd5. \u53e6\u5916 \u5982\u679c\u7528\u4e0b\u9762\u7684\u65b9\u6cd5, \u6709\u53ef\u80fd\u51fa\u73b0\u7684\u95ee\u9898\u5c31\u662f\u6709\u53ef\u80fdreverse \u4e4b\u540e\u7684integer\u4f1aoverflow, \u8fd9\u4e2a\u95ee\u9898\u7684\u89e3\u51b3\u65b9\u6cd5, \u5f53\u7136\u53ef\u4ee5\u662f\u7528long long \u6765\u627f\u63a5reverse\u4e4b\u540e\u7684integer, \u4f46\u662f\u8fd9\u6837\u5c31\u663e\u5f97\u592a\u4e0dgeneral\u4e86, \u6211\u4e5f\u60f3\u8d77\u4e86atoi\u51fd\u6570\u91cc\u9762\u5f53\u65f6\u60f3\u5230\u7684\u4e00\u4e2a\u95ee\u9898, \u5982\u679coverflow\u4e86\u600e\u4e48\u529e?(\u7ee7\u7eed\u5ef6\u4f38, \u6211\u60f3\u5230\u6709\u6b21\u770b\u5230\u8ba8\u8bba\u5982\u4f55\u5224\u65adint\u7684\u4e58\u6cd5\u662f\u5426overflow\u4e86, \u6709\u4e2a\u7b80\u5355\u7684\u65b9\u6cd5\u662f\u628a\u4e58\u6cd5\u5f97\u51fa\u7684\u7ed3\u679c\u5904\u4ee5\u4efb\u4f55\u4e00\u4e2a\u4e58\u6570, \u770b\u7ed3\u679c\u662f\u4e0d\u662f\u53e6\u4e00\u4e2a\u4e58\u6570) \u8fd9\u4e2a\u662f\u5927\u5b98\u4eba\u6307\u51fa\u7684\u53ef\u80fd\u51fa\u73b0\u7684\u4e00\u4e2a\u95ee\u9898, … Continue reading “\u6bcf\u65e55\u9898–0629”<\/span><\/a><\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[10],"tags":[],"class_list":["post-193","post","type-post","status-publish","format-standard","hentry","category-programming-and-algorithm"],"_links":{"self":[{"href":"https:\/\/hw.minilinux.net\/index.php?rest_route=\/wp\/v2\/posts\/193","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/hw.minilinux.net\/index.php?rest_route=\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/hw.minilinux.net\/index.php?rest_route=\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/hw.minilinux.net\/index.php?rest_route=\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/hw.minilinux.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcomments&post=193"}],"version-history":[{"count":13,"href":"https:\/\/hw.minilinux.net\/index.php?rest_route=\/wp\/v2\/posts\/193\/revisions"}],"predecessor-version":[{"id":639,"href":"https:\/\/hw.minilinux.net\/index.php?rest_route=\/wp\/v2\/posts\/193\/revisions\/639"}],"wp:attachment":[{"href":"https:\/\/hw.minilinux.net\/index.php?rest_route=%2Fwp%2Fv2%2Fmedia&parent=193"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/hw.minilinux.net\/index.php?rest_route=%2Fwp%2Fv2%2Fcategories&post=193"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/hw.minilinux.net\/index.php?rest_route=%2Fwp%2Fv2%2Ftags&post=193"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}