\u524d\u8a00<\/p>\n
\u4e3a\u4ec0\u4e48\u4f60\u4ee3\u7801\u80fd\u8dd1，\u4f46\u9762\u8bd5\u603b\u88ab\u6302？<\/p>\n
\u4e3a\u4ec0\u4e48LeetCode\u80fdAC，\u4e00\u5230\u5927\u5382\u7b14\u8bd5\u5c31\u8d85\u65f6？<\/p>\n
\u4e3a\u4ec0\u4e48\u4e24\u4e2a\u4eba\u5199\u51fa\u540c\u6837\u529f\u80fd\u7684\u4ee3\u7801，\u4e00\u4e2a\u6ee1\u5206\u3001\u4e00\u4e2a\u76f4\u63a5\u6dd8\u6c70？<\/p>\n
\u7b54\u6848\u53ea\u6709\u4e00\u4e2a：\u4f60\u4e0d\u61c2\u65f6\u95f4\u590d\u6742\u5ea6\u3002<\/p>\n
\u7edd\u5927\u591a\u6570\u7f16\u7a0b\u65b0\u624b\u3001\u5927\u4e8c\u5927\u4e09\u540c\u5b66，\u90fd\u5361\u5728\u540c\u4e00\u4e2a\u74f6\u9888：<\/p>\n
\u53ea\u4f1a\u5199\u300c\u80fd\u8dd1\u7684\u4ee3\u7801\u300d，\u4e0d\u4f1a\u5199\u300c\u9ad8\u6548\u7684\u4ee3\u7801\u300d\u3002<\/p>\n
\u65f6\u95f4\u590d\u6742\u5ea6\u662f\u6240\u6709\u7b97\u6cd5\u7684\u5730\u57fa，\u4e5f\u662f\u9762\u8bd5\u5fc5\u8003\u7b2c\u4e00\u95ee\u3002<\/p>\n
\u4eca\u5929\u7528\u6700\u901a\u4fd7\u3001\u96f6\u6666\u6da9\u3001\u5168\u5b9e\u6218\u7684\u65b9\u5f0f，\u5e26\u4f60\u5f7b\u5e95\u5403\u900f\u65f6\u95f4\u590d\u6742\u5ea6，\u770b\u5b8c\u76f4\u63a5\u540a\u625380%\u65b0\u624b！<\/p>\n
\u4e00\u3001\u5230\u5e95\u4ec0\u4e48\u662f\u65f6\u95f4\u590d\u6742\u5ea6？（\u4eba\u8bdd\u7248）<\/p>\n
\u4e0d\u8c08\u6559\u79d1\u4e66\u5e9f\u8bdd\u3002<\/p>\n
\u65f6\u95f4\u590d\u6742\u5ea6：\u7528\u6765\u9884\u5224\u4f60\u7684\u4ee3\u7801\u8fd0\u884c\u901f\u5ea6\u7684\u6570\u5b66\u6807\u51c6\u3002<\/p>\n
\u5b83\u4e0d\u770b\u4ee3\u7801\u884c\u6570\u3001\u4e0d\u770b\u7535\u8111\u914d\u7f6e，\u53ea\u770b：<\/p>\n
\u6570\u636e\u53d8\u591a\u7684\u65f6\u5019，\u4f60\u7684\u4ee3\u7801\u4f1a\u4e0d\u4f1a\u8d8a\u6765\u8d8a\u6162？\u6162\u5f97\u6709\u591a\u5feb？<\/p>\n
\u7b97\u6cd5\u7b49\u7ea7\u4ece\u4f18\u5230\u52a3：<\/p>\n
$$O(1) < O(logn) < O(n) < O(nlogn) < O(n^2) < O(2^n) < O(n!)$$<\/p>\n
\u53ea\u8981\u4f60\u80fd\u5206\u6e05\u8fd97\u4e2a\u7b49\u7ea7，\u4f60\u7684\u7b97\u6cd5\u6c34\u5e73\u76f4\u63a5\u8fdb\u9636\u4e00\u6863\u3002<\/p>\n
\u4e8c\u3001\u4e03\u79cd\u590d\u6742\u5ea6\u9010\u53e5\u62c6\u89e3（\u5e26\u771f\u5b9e\u4ee3\u7801\u573a\u666f）<\/p>\n
1. O(1) \u5e38\u6570\u7ea7 \u2014\u2014 \u6700\u4f18\u89e3<\/p>\n
\u65e0\u8bba\u6570\u636e\u591a\u5c11，\u6267\u884c\u65f6\u95f4\u4e0d\u53d8<\/p>\n
\u5e38\u89c1\u573a\u666f：<\/p>\n
– \u53d8\u91cf\u8d4b\u503c<\/p>\n
– \u6570\u7ec4\u968f\u673a\u53d6\u503c<\/p>\n
– \u7b80\u5355\u56db\u5219\u8fd0\u7b97<\/p>\n
\u793a\u4f8b：<\/p>\n
int a = arr[10];<\/p>\n
\u7279\u70b9：\u6c38\u8fdc\u4e0d\u8d85\u65f6，\u7b97\u6cd5\u5929\u82b1\u677f\u3002<\/p>\n
\u00a0<\/p>\n
—<\/p>\n
2. O(log n) \u5bf9\u6570\u7ea7 \u2014\u2014 \u9762\u8bd5\u6700\u7231<\/p>\n
\u6570\u636e\u7ffb\u500d，\u6267\u884c\u6b21\u6570\u53ea+1<\/p>\n
\u5178\u578b\u7b97\u6cd5：\u4e8c\u5206\u67e5\u627e<\/p>\n
100\u4e07\u7684\u6570\u636e，\u5faa\u73af\u53ea\u8dd120\u6b21，\u8fd9\u5c31\u662f\u4e3a\u4ec0\u4e48\u4e8c\u5206\u65e0\u654c\u5feb\u3002<\/p>\n
\u6240\u6709\u80fd\u4e0d\u65ad\u300c\u780d\u6389\u4e00\u534a\u6570\u636e\u300d\u7684\u7b97\u6cd5，\u90fd\u662f logn<\/p>\n
\u00a0<\/p>\n
—<\/p>\n
3. O(n) \u7ebf\u6027\u7ea7 \u2014\u2014 \u6b63\u5e38\u904d\u5386<\/p>\n
\u6570\u636e\u591a\u5927，\u5faa\u73af\u591a\u5c11\u6b21<\/p>\n
\u573a\u666f：\u5355for\u5faa\u73af\u3001\u904d\u5386\u6570\u7ec4\u3001\u904d\u5386\u94fe\u8868<\/p>\n
\u80fd\u8fc7\u7edd\u5927\u591a\u6570\u5e38\u89c4\u9898\u76ee，\u4f46\u662f\u6570\u636e\u91cf10\u4e07+\u4f1a\u5403\u529b<\/p>\n
\u00a0<\/p>\n
—<\/p>\n
4. O(n log n) \u7ebf\u6027\u5bf9\u6570 \u2014\u2014 \u5de5\u4e1a\u7ea7\u6700\u4f18\u6392\u5e8f<\/p>\n
\u6700\u5e38\u89c1：\u5feb\u901f\u6392\u5e8f\u3001\u5f52\u5e76\u6392\u5e8f\u3001Arrays.sort()<\/p>\n
\u5927\u5382\u9879\u76ee\u3001\u5e95\u5c42\u6e90\u7801\u5168\u90e8\u662f\u8fd9\u4e2a\u590d\u6742\u5ea6\u3002<\/p>\n
\u53ef\u4ee5\u5904\u7406\u767e\u4e07\u7ea7\u3001\u5343\u4e07\u7ea7\u6570\u636e<\/p>\n
\u8fd9\u662f\u5de5\u7a0b\u91cc\u6700\u5b9e\u7528\u3001\u6700\u5e73\u8861\u7684\u590d\u6742\u5ea6<\/p>\n
\u00a0<\/p>\n
—<\/p>\n
5. O(n\u00b2) \u5e73\u65b9\u7ea7 \u2014\u2014 \u65b0\u624b\u91cd\u707e\u533a<\/p>\n
\u53cc\u91cdfor\u5faa\u73af<\/p>\n
\u66b4\u529b\u679a\u4e3e\u3001\u4e24\u6570\u6c42\u548c\u66b4\u529b\u5199\u6cd5\u3001\u5192\u6ce1\u6392\u5e8f<\/p>\n
\u6570\u636e\u91cf 1000 \u6ca1\u95ee\u9898<\/p>\n
\u6570\u636e\u91cf 10000 \u76f4\u63a5\u8d85\u65f6\u5361\u6b7b<\/p>\n
\u7b14\u8bd5\u7ffb\u8f66\u7b2c\u4e00\u540d：O(n\u00b2)\u66b4\u529b\u5199\u6cd5<\/p>\n
\u00a0<\/p>\n
—<\/p>\n
6. O(2\u207f) \u6307\u6570\u7ea7<\/p>\n
\u9012\u5f52\u66b4\u529b\u679a\u4e3e\u3001\u5b50\u96c6\u679a\u4e3e<\/p>\n
\u6570\u636en=30 \u76f4\u63a5\u7206\u70b8，\u5b8c\u5168\u65e0\u6cd5\u5546\u7528<\/p>\n
\u00a0<\/p>\n
—<\/p>\n
7. O(n!) \u9636\u4e58\u7ea7<\/p>\n
\u5168\u6392\u5217\u3001\u66b4\u529b\u7a77\u4e3e\u6240\u6709\u53ef\u80fd\u6027<\/p>\n
\u57fa\u672c\u5c5e\u4e8e\u53ea\u80fd\u8dd1n<12\u7684\u73a9\u5177\u4ee3\u7801<\/p>\n
\u4e09\u3001\u9762\u8bd5\u5b98\u6700\u7231\u95ee：\u4e3a\u4ec0\u4e48 O(n\u00b2) \u4e00\u5b9a\u4f1a\u8d85\u65f6？<\/p>\n
\u7ed9\u4f60\u4e00\u7ec4\u771f\u5b9e\u6570\u636e\u5bf9\u6bd4（\u79d2\u61c2）<\/p>\n
– n = 100：O(n\u00b2)=1\u4e07\u6b21（\u968f\u4fbf\u8dd1）<\/p>\n
– n = 1000：O(n\u00b2)=100\u4e07\u6b21（\u52c9\u5f3a\u8dd1）<\/p>\n
– n = 10000：O(n\u00b2)=1\u4ebf\u6b21 （\u8d85\u65f6）<\/p>\n
– n = 100000：O(n\u00b2)=100\u4ebf\u6b21 （\u76f4\u63a5\u5361\u6b7b）<\/p>\n
\u5927\u5382\u7b14\u8bd5\u6570\u636e\u91cf\u6700\u4f4e\u90fd\u662f 1e4\u30011e5<\/p>\n
\u6240\u4ee5：\u53cc\u91cd\u5faa\u73af\u66b4\u529b\u5199\u6cd5，\u4ece\u4e00\u5f00\u59cb\u5c31\u662f\u9519\u7684<\/p>\n
\u65b0\u624b\u6700\u5927\u8bef\u533a：<\/p>\n
\u53ea\u8981\u6837\u4f8b\u80fd\u8fc7 = \u4ee3\u7801\u6b63\u786e<\/p>\n
\u771f\u5b9e\u8bc4\u5224\u6807\u51c6：\u5927\u6570\u636e\u4e0b\u4e0d\u8d85\u65f6，\u624d\u662f\u6b63\u786e\u4ee3\u7801<\/p>\n
\u56db\u3001\u624b\u628a\u624b\u6559\u4f60：\u5982\u4f55\u4e00\u773c\u770b\u51fa\u590d\u6742\u5ea6<\/p>\n
\u7ed9\u5927\u5bb6\u4e00\u4e2a\u4e07\u80fd\u53e3\u8bc0<\/p>\n
1. \u65e0\u5faa\u73af \u2192 O(1)<\/p>\n
2. \u5355\u5c42\u5faa\u73af \u2192 O(n)<\/p>\n
3. \u53cc\u5c42\u5faa\u73af \u2192 O(n\u00b2)<\/p>\n
4. \u6bcf\u6b21\u6298\u534a（\u4e8c\u5206）\u2192 O(logn)<\/p>\n
5. \u6392\u5e8f+\u904d\u5386 \u2192 O(nlogn)<\/p>\n
6. \u9012\u5f52\u4e0d\u526a\u679d \u2192 O(2\u207f)<\/p>\n
\u4e0d\u7528\u8ba1\u7b97\u3001\u4e0d\u7528\u63a8\u5bfc，\u4e00\u773c\u5224\u5b9a<\/p>\n
\u4e94\u3001\u771f\u5b9e\u9762\u8bd5\u4f18\u5316\u6848\u4f8b（\u4ece\u8d85\u65f6\u5230\u6ee1\u5206）<\/p>\n
\u9898\u76ee：\u67e5\u627e\u6570\u7ec4\u4e24\u6570\u4e4b\u548c<\/p>\n
\u65b0\u624b\u8d85\u65f6\u5199\u6cd5 O(n\u00b2)<\/p>\n
\u53cc\u91cd\u5faa\u73af\u679a\u4e3e\u6240\u6709\u7ec4\u5408，\u6570\u636e\u91cf\u5927\u76f4\u63a5\u8d85\u65f6<\/p>\n
\u4f18\u5316\u6ee1\u5206\u5199\u6cd5 O(n)<\/p>\n
\u54c8\u5e0c\u8868\u4e00\u6b21\u904d\u5386，\u7a7a\u95f4\u6362\u65f6\u95f4<\/p>\n
\u8fd9\u5c31\u662f\u9762\u8bd5\u6700\u6838\u5fc3\u7684\u7b97\u6cd5\u4f18\u5316\u601d\u7ef4<\/p>\n
\u4e0d\u662f\u5b9e\u73b0\u529f\u80fd，\u662f\u964d\u590d\u6742\u5ea6<\/p>\n
\u516d\u3001\u65b0\u624b\u5fc5\u80cc：\u7b14\u8bd5\u590d\u6742\u5ea6\u901a\u5173\u6807\u51c6<\/p>\n
\u8bb0\u4f4f\u8fd9\u5957\u6807\u51c6，\u5237\u9898\u6c38\u8fdc\u4e0d\u8d85\u65f6：<\/p>\n
1. n \u2264 1e5 \u5fc5\u987b O(n) \u6216 O(n logn)<\/p>\n
2. n \u2264 1e6 \u53ea\u80fd O(n)<\/p>\n
3. n \u2264 1e3 \u53ef\u4ee5\u52c9\u5f3a O(n\u00b2)<\/p>\n
4. \u53ea\u8981\u770b\u5230\u5927\u6570\u636e，\u7acb\u523b\u653e\u5f03\u66b4\u529b<\/p>\n
\u6240\u6709\u7b97\u6cd5\u9898\u7684\u89e3\u9898\u601d\u8def，\u90fd\u662f\u6839\u636e\u590d\u6742\u5ea6\u53cd\u5411\u63a8\u5bfc\u7684！<\/p>\n
\u4e03\u3001\u5199\u5728\u6700\u540e（\u63d0\u5347\u8ba4\u77e5）<\/p>\n
\u5f88\u591a\u4eba\u4ee5\u4e3a\u7b97\u6cd5\u662f\u5237\u9898\u3001\u662f\u5957\u8def\u3001\u662f\u6a21\u677f\u3002<\/p>\n
\u771f\u6b63\u7684\u7b97\u6cd5\u6838\u5fc3，\u662f\u590d\u6742\u5ea6\u601d\u7ef4\u3002<\/p>\n
\u770b\u61c2\u590d\u6742\u5ea6，\u4f60\u624d\u80fd：<\/p>\n
– \u505a\u9898\u4e0d\u8d85\u65f6<\/p>\n
– \u9762\u8bd5\u7b54\u5f97\u51fa\u539f\u7406<\/p>\n
– \u5199\u5f97\u51fa\u5de5\u7a0b\u7ea7\u9ad8\u6548\u4ee3\u7801<\/p>\n
– \u771f\u6b63\u4ece\u201c\u4f1a\u6572\u4ee3\u7801\u201d\u8fdb\u9636\u4e3a\u201c\u61c2\u7b97\u6cd5\u7684\u5f00\u53d1\u8005\u201d<\/p>\n
\u540e\u7eed\u6211\u4f1a\u6301\u7eed\u66f4\u65b0\u7b97\u6cd5\u5e95\u5c42\u601d\u7ef4\u7cfb\u5217\u3001\u9762\u8bd5\u5fc5\u8003\u624b\u6495\u7b97\u6cd5，\u60f3\u5b66\u771f\u6b63\u80fd\u6da8\u85aa\u3001\u80fd\u62ffoffer\u7684\u7b97\u6cd5，\u6b22\u8fce\u5173\u6ce8！<\/p>\n
\u65b0\u624b\u6536\u85cf\u53e3\u8bc0<\/p>\n
**\u5e38\u6570\u6700\u5feb\u5bf9\u6570\u7a33，\u7ebf\u6027\u6b63\u5e38\u6392\u5e8f\u51c6；<\/p>\n
\u53cc\u91cd\u5faa\u73af\u5fc5\u8d85\u65f6，\u6307\u6570\u9636\u4e58\u4e0d\u8981\u5fcd\u3002**<\/p>\n
\u00a0<\/p>\n
—<\/p>\n
\u6807\u7b7e：\u7b97\u6cd5\u3001\u65f6\u95f4\u590d\u6742\u5ea6\u3001\u6570\u636e\u7ed3\u6784\u3001Java\u7b97\u6cd5\u3001\u7f16\u7a0b\u9762\u8bd5\u3001\u7b97\u6cd5\u4f18\u5316\u3001\u5927\u5b66\u751f\u7f16\u7a0b\u3001LeetCode<\/p>\n
\u539f\u521b\u5e72\u8d27，\u70b9\u8d5e\u6536\u85cf，\u52a9\u4f60\u5f7b\u5e95\u6446\u8131\u4ee3\u7801\u8d85\u65f6\u95ee\u9898！<\/p>\n
\u00a0<\/p>\n","protected":false},"excerpt":{"rendered":"
\u524d\u8a00\u4e3a\u4ec0\u4e48\u4f60\u4ee3\u7801\u80fd\u8dd1，\u4f46\u9762\u8bd5\u603b\u88ab\u6302？\u4e3a\u4ec0\u4e48LeetCode\u80fdAC，\u4e00\u5230\u5927\u5382\u7b14\u8bd5\u5c31\u8d85\u65f6？\u4e3a\u4ec0\u4e48\u4e24\u4e2a\u4eba\u5199\u51fa\u540c\u6837\u529f\u80fd\u7684\u4ee3\u7801，\u4e00\u4e2a\u6ee1\u5206\u3001\u4e00\u4e2a\u76f4\u63a5\u6dd8\u6c70？\u7b54\u6848\u53ea\u6709\u4e00\u4e2a：\u4f60\u4e0d\u61c2\u65f6\u95f4\u590d\u6742\u5ea6\u3002\u7edd\u5927\u591a\u6570\u7f16\u7a0b\u65b0\u624b\u3001\u5927\u4e8c\u5927\u4e09\u540c\u5b66，\u90fd\u5361\u5728\u540c\u4e00\u4e2a\u74f6\u9888：\u53ea\u4f1a\u5199\u300c\u80fd\u8dd1\u7684\u4ee3\u7801\u300d，\u4e0d\u4f1a\u5199\u300c\u9ad8\u6548\u7684\u4ee3\u7801\u300d\u3002\u65f6\u95f4\u590d\u6742\u5ea6\u662f\u6240\u6709\u7b97\u6cd5\u7684\u5730\u57fa，\u4e5f\u662f\u9762\u8bd5\u5fc5\u8003\u7b2c\u4e00\u95ee\u3002\u4eca\u5929\u7528\u6700\u901a<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[427,176],"topic":[],"class_list":["post-110983","post","type-post","status-publish","format-standard","hentry","category-server","tag-427","tag-176"],"yoast_head":"\n