题目
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 in ascending from left to right.
- Integers in each column are sorted in ascending from top to bottom.
题意
给定一个矩阵，矩阵中每一行从左到右升序排序，每一列从上到下升序排序；寻找target值是否在矩阵中
题解
利用有序的特点，从右上角开始寻找
1）若右上角大于目标值，则范围去掉当前最后一列
2）若右上角小于目标值，则范围去掉当前第一行
代码
func searchMatrix(matrix [][]int, target int) bool {
M := len(matrix)
if M==0{
return false
}
N := len(matrix[0])
if N==0{
return false
}
m := 0
n := N-1
for m<M&&n>=0{
if matrix[m][n]==target{
return true
}
if matrix[m][n]>target{
n = n - 1
}else{
m = m + 1
}
}
return false
}
总结
因为剑指offer里面也做过，思路也比较简单，所以直接就做出来了。
