leetcode_Search a 2D Matrix

题意：在一个排序好的二维数组里，找出指定元素

注意：二分查找的“模板”，每一个细节都要注意。 bool searchMatrix(vector<vector<int>>& matrix, int target) {
int m,n,i,j,k,left=0,right=0,middle=0;
if(matrix.size()==0) return false;
m=matrix.size();
n=matrix[0].size();
left=0;
right=matrix.size()-1;
while(left<right)
{
middle=(left+right)/2;
if(matrix[middle][0]<=target&&matrix[middle+1][0]>target) break;
if(matrix[middle][0]<target) left=middle+1;
else right=middle-1;
}
if(left==m-1 ||matrix[left][0]<=target&&matrix[left+1][0]>target) middle=left;
left=0;
right=n-1;
i=middle;
while(left<right)
{
middle=(left+right)/2;
if(matrix[i][middle]==target) return true;
if(matrix[i][middle]<target) left=middle+1;
else right=middle-1;
}
if(matrix[i][left]==target) return true;
return false;
}