From ed9b2736d4098006cd8deeeacdea46d1283fd76e Mon Sep 17 00:00:00 2001 From: CyC2018 <1029579233@qq.com> Date: Tue, 27 Feb 2018 16:48:09 +0800 Subject: [PATCH] auto commit --- notes/剑指 offer 题解.md | 22 +++++++++++++--------- 1 file changed, 13 insertions(+), 9 deletions(-) diff --git a/notes/剑指 offer 题解.md b/notes/剑指 offer 题解.md index 747a7ea1..581ba92a 100644 --- a/notes/剑指 offer 题解.md +++ b/notes/剑指 offer 题解.md @@ -19,7 +19,7 @@ * [15. ¶þ½øÖÆÖÐ 1 µÄ¸öÊý](#15-¶þ½øÖÆÖÐ-1-µÄ¸öÊý) * [µÚÈýÕ ¸ßÖÊÁ¿µÄ´úÂë](#µÚÈýÕÂ-¸ßÖÊÁ¿µÄ´úÂë) * [16. ÊýÖµµÄÕûÊý´Î·½](#16-ÊýÖµµÄÕûÊý´Î·½) - * [18. ɾ³ýÁ´±íÖÐÖظ´µÄ½áµã](#18-ɾ³ýÁ´±íÖÐÖظ´µÄ½áµã) + * [18.2 ɾ³ýÁ´±íÖÐÖظ´µÄ½áµã](#182-ɾ³ýÁ´±íÖÐÖظ´µÄ½áµã) * [19. ÕýÔò±í´ïʽƥÅä](#19-ÕýÔò±í´ïʽƥÅä) * [20. ±íʾÊýÖµµÄ×Ö·û´®](#20-±íʾÊýÖµµÄ×Ö·û´®) * [21. µ÷ÕûÊý×é˳ÐòʹÆæÊýλÓÚżÊýÇ°Ãæ](#21-µ÷ÕûÊý×é˳ÐòʹÆæÊýλÓÚżÊýÇ°Ãæ) @@ -541,12 +541,16 @@ int maxProductAfterCuttin(int length) { ## 15. ¶þ½øÖÆÖÐ 1 µÄ¸öÊý +ʹÓÿ⺯Êý£º + ```java public int NumberOf1(int n) { return Integer.bitCount(n); } ``` +O(lgM) ʱ¼ä¸´ÔӶȽⷨ£¬ÆäÖÐ M ±íʾ 1 µÄ¸öÊý£º + n&(n-1) ¸ÃλÔËËãÊÇÈ¥³ý n µÄλ¼¶±íʾÖÐ×îµÍµÄÄÇһλ¡£ÀýÈç¶ÔÓÚ¶þ½øÖƱíʾ 10110100£¬¼õÈ¥ 1 µÃµ½ 10110011£¬ÕâÁ½¸öÊýÏàÓëµÃµ½ 10110000¡£ ```java @@ -558,7 +562,6 @@ public int NumberOf1(int n) { } return cnt; } - ``` # µÚÈýÕ ¸ßÖÊÁ¿µÄ´úÂë @@ -580,7 +583,7 @@ public double Power(double base, int exponent) { } ``` -## 18. ɾ³ýÁ´±íÖÐÖظ´µÄ½áµã +## 18.2 ɾ³ýÁ´±íÖÐÖظ´µÄ½áµã ```java public ListNode deleteDuplication(ListNode pHead) { @@ -641,6 +644,10 @@ public boolean isNumeric(char[] str) { ## 21. µ÷ÕûÊý×é˳ÐòʹÆæÊýλÓÚżÊýÇ°Ãæ +**ÌâÄ¿ÒªÇó** + +±£Ö¤ÆæÊýºÍÆæÊý£¬Å¼ÊýºÍżÊýÖ®¼äµÄÏà¶ÔλÖò»±ä£¬ÕâºÍÊé±¾²»Ì«Ò»Ñù¡£ + ʱ¼ä¸´ÔÓ¶È : O(n2) ¿Õ¼ä¸´ÔÓ¶È : O(1) @@ -695,8 +702,6 @@ public ListNode FindKthToTail(ListNode head, int k) { } ``` - - ## 23. Á´±íÖл·µÄÈë¿Ú½áµã ```java @@ -1455,8 +1460,6 @@ public ListNode FindFirstCommonNode(ListNode pHead1, ListNode pHead2) { ## 53 Êý×ÖÔÚÅÅÐòÊý×éÖгöÏֵĴÎÊý - - ```java public int GetNumberOfK(int[] array, int k) { int l = 0, h = array.length - 1; @@ -1735,8 +1738,9 @@ public int maxProfit(int[] prices) { ```java public int Sum_Solution(int n) { - if(n == 0) return 0; - return n + Sum_Solution(n - 1); + int sum = n; + boolean b = (n > 0) && ((sum += Sum_Solution(n - 1)) > 0); + return sum; } ```