[LeetCode]#821. Shortest Distance to a Character

Environment: Python 3.7

Key technique: enumerate

Given a string S and a character C, return an array of integers representing the shortest distance from the character C in the string.

Example 1:

Input: S = "loveleetcode", C = 'e'
Output: [3, 2, 1, 0, 1, 0, 0, 1, 2, 2, 1, 0]

Note:

1. S string length is in [1, 10000].
2. C is a single character, and guaranteed to be in string S.
3. All letters in S and C are lowercase.

Analysis:

As below example, follow below steps.

1. Find e in S location [3,5,6,11]
2. We can calculate letter distance based on e location. For example, I is [3,5,6,11]
3. Find minimum is 3.
4. Therefore, the answer is [3,2,1,0,1,0,0,1,2,2,1,0]

Solution:

class Solution:
    def shortestToChar(self, S, C):
        index_nums=[]
        for i, letter in enumerate(S):
            if letter == C: 
                index_nums.append(i)
        ans = []
        l=len(S)
        l2=len(index_nums)
        d=[None]*l2
        for j in range(l):
            for k in range(l2):
                d[k]=abs(j-index_nums[k])
            ans.append(min(d))
        return ans

Submitted result:

Reference:

https://blog.csdn.net/DreamerLHQ/article/details/80116531