标签：style blog color io os ar for div art
Given a sorted array of integers, find the starting and ending position of a given target value.
Your algorithm‘s runtime complexity must be in the order of O(log n).
If the target is not found in the array, return [-1, -1].
For example,
Given [5, 7, 7, 8, 8, 10] and target value 8,
return [3, 4].
算法：该算法来源于网络，用二分查找最左最右的位置，代码如下：
1 class Solution { 2 public: 3 vector<int> searchRange(int A[], int n, int target) { 4 int l=findPos(A,0,n-1,target,true); 5 int r=findPos(A,0,n-1,target,false); 6 vector<int> result; 7 result.push_back(l); 8 result.push_back(r); 9 return result; 10 } 11 int findPos(int a[],int beg,int end,int key,bool findLeft) 12 { 13 if(beg>end) return -1; 14 int mid=(beg+end)/2; 15 if(a[mid]==key) 16 { 17 int pos=findLeft?findPos(a,beg,mid-1,key,findLeft):findPos(a,mid+1,end,key,findLeft); 18 return pos==-1?mid:pos; 19 } 20 else if(a[mid]<key) 21 { 22 findPos(a,mid+1,end,key,findLeft); 23 } 24 else if(a[mid]>key) 25 { 26 findPos(a,beg,mid-1,key,findLeft); 27 } 28 } 29 };
标签：style blog color io os ar for div art
原文地址：http://www.cnblogs.com/sqxw/p/3976814.html
