1 class Solution {
2 public:
3 bool searchMatrix(vector<vector<int> > &matrix, int target) {
4 // IMPORTANT: Please reset any member data you declared, as
5 // the same Solution instance will be reused for each test case.
6 int m =matrix.size();
7 if (m<=0)
8 return false;
9 int n = matrix[0].size();
10 if (n<=0)
11 return false;
12 int left=0, right=m-1, mid;
13 while(left<=right){
14 mid = (left+right)/2;
15 if (matrix[mid][0]<=target && matrix[mid][n-1]>=target)
16 break;
17 if (matrix[mid][0]>target)
18 right=mid-1;
19 if (matrix[mid][n-1]<target)
20 left = mid+1;
21 }
22 vector<int> row = matrix[mid];
23 if (row[0]>target || row[n-1]<target)
24 return false;
25 left = 0, right = n-1;
26 while (left<=right){
27 mid = (left+right)/2;
28 if (row[mid]==target)
29 return true;
30 if(row[mid]>target)
31 right = mid-1;
32 else left = mid+1;
33 }
34 return false;
35 }
36 };
