[LeetCode]#1266. Minimum Time Visiting All Points

Environment: Python 3.7

Key technique: abs

On a plane there are n points with integer coordinates points[i] = [xi, yi]. Your task is to find the minimum time in seconds to visit all points.

You can move according to the next rules:

• In one second always you can either move vertically, horizontally by one unit or diagonally (it means to move one unit vertically and one unit horizontally in one second).
• You have to visit the points in the same order as they appear in the array.

Example 1:

Input: points = [[1,1],[3,4],[-1,0]]
Output: 7
Explanation: One optimal path is [1,1] -> [2,2] -> [3,3] -> [3,4] -> [2,3] -> [1,2] -> [0,1] -> [-1,0]   
Time from [1,1] to [3,4] = 3 seconds 
Time from [3,4] to [-1,0] = 4 seconds
Total time = 7 seconds

Example 2:

Input: points = [[3,2],[-2,2]]
Output: 5

Constraints:

• points.length == n
• 1 <= n <= 100
• points[i].length == 2
• -1000 <= points[i][0], points[i][1] <= 1000

Analysis:

As below, we can find green road need 4 sec, and blue road need 2 sec. Namely, one “/” way can be replace two “| “and “ —”. We can converted as Max( (x2-x1),(y2-y1)).

Solution:

class Solution:
    def minTimeToVisitAllPoints(self, points):
        size=len(points)
        total_t=0
        for i in range(size-1):
            x=abs(points[i][0]-points[i+1][0])
            y=abs(points[i][1]-points[i+1][1])
            total_t+=max(x,y)
        return total_t

Submitted result:

Reference:

https://leetcode.com/problems/minimum-time-visiting-all-points/discuss/582967/Python-easy-to-read%3A-100-less-memory-faster-than-86