74. 搜索二维矩阵 @Python @Go

原题

https://leetcode.cn/problems/search-a-2d-matrix/description/

思路

二分查找

复杂度

时间：O(m * log(n))
空间：O(1)

Python代码

class Solution:
    def searchMatrix(self, matrix: List[List[int]], target: int) -> bool:
        m = len(matrix)
        n = len(matrix[0])        
        for i in range(m):
            if target > matrix[i][-1]:
                continue 
            l = 0 
            r = n 
            while l < r:
                mid = (l + r) // 2 
                if target == matrix[i][mid]:
                    return True 
                elif target > matrix[i][mid]:
                    l = mid + 1 
                else: 
                    r = mid 
        return False
       

Go代码

func searchMatrix(matrix [][]int, target int) bool {
	m, n := len(matrix), len(matrix[0])
	for i := 0; i < m; i++ {
		if target > matrix[i][n-1] {
			continue
		}
		l, r := 0, n
		for l < r {
			mid := (l + r) / 2
			if target == matrix[i][mid] {
				return true
			} else if target > matrix[i][mid] {
				l = mid + 1
			} else {
				r = mid
			}
		}
	}
	return false
}