Search a 2D Matrix II Java Solutions

Write an efficient algorithm, searches for a value in a m x n Matrix. This matrix has the following properties:

• Integers in each row is sorted in ascending from left to right.
• Integers in each column is sorted in ascending from top to bottom.

For example,

Consider the following matrix:

[  [1,   4,  7, one, a],  [2,   5, 8,, +  ],  [3,   6,  9, +, +],  [10, 13, 14, 17,  [18, 21, 23, 26, 30]

Given target = 5 , return true .

Given target = 20 , return false .

1  Public classSolution {2      Public BooleanSearchmatrix (int[] Matrix,inttarget) {3         if(Matrix.length = = 0 | | matrix[0].length = = 0)return false;4         inti = 0,j = Matrix[0].length-1;5          while(I < matrix.length && J >= 0){6             if(Matrix[i][j] = = target)return true;7             if(Matrix[i][j] < target) i++;8             Elsej--;9         }Ten         return false; One     } A}

The matrix is special and can be compared from the top right x, if target > x, then to the next line, if Target < X, then go back one column. The topic has appeared in the beauty of programming.

Solution 2: The problem can also be found using the dichotomy method.

Search a 2D Matrix II Java Solutions