Search a 2D Matrix

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

• Integers in each row are sorted from left to right.
• The first integer of each row is greater than the last integer of the previous row.

For example,

Consider the following matrix:

[
  [1,   3,  5,  7],
  [10, 11, 16, 20],
  [23, 30, 34, 50]
]

Given target = 3, return true.

• 在数组中，查找是否存在target这个数

bool searchMatrix(int** matrix, int matrixRowSize, int matrixColSize, int target) {
    int i = 0;
    for(; i < matrixRowSize; i++) 
    {
        if(matrix[i][matrixColSize - 1] >= target)
            break;
    }
    if(i == matrixRowSize)
        return 0;
    for(int j = 0; j < matrixColSize; j++)
    {
        if(matrix[i][j] == target)
            return 1;
    }
    return 0;
}

• 先查找每行最后一个值，对比target；得到哪行后对比该行

Search a 2D Matrix

原文：http://www.cnblogs.com/dylqt/p/4979746.html