leetcode74.搜索二维矩阵

把二维数组展开成一维，发现随着索引增加，值增大，那么其实这就是普通的二分查找

class Solution {
    public boolean searchMatrix(int[][] matrix, int target) {
        int m=matrix.length,n=matrix[0].length;
        int left=0,right=m*n-1;
        while(left<=right){
            int mid=(right-left)/2+left;

            int row=mid/n;
            int col=mid%n;
            if(matrix[row][col]==target)
                return true;
            else if(target<matrix[row][col])
                right=mid-1;
            else    
                left=mid+1;
        }
        return false;
    }
}