花花酱 LeetCode 2185. Counting Words With a Given Prefix

zxi — Sun, 27 Feb 2022 05:10:38 +0000

You are given an array of strings words and a string pref.

Return the number of strings in words that contain pref as a prefix.

A prefix of a string s is any leading contiguous substring of s.

Example 1:

Input: words = ["pay","attention","practice","attend"], pref = "at"
Output: 2
Explanation: The 2 strings that contain "at" as a prefix are: "attention" and "attend".

Example 2:

Input: words = ["leetcode","win","loops","success"], pref = "code"
Output: 0
Explanation: There are no strings that contain "code" as a prefix.

Constraints:

1 <= words.length <= 100
1 <= words[i].length, pref.length <= 100
words[i] and pref consist of lowercase English letters.

Solution: Straight forward

We can use std::count_if and std::string::find.

Time complexity: O(n*l)
Space complexity: O(1)

C++

// Author: Huahua
class Solution {
public:
  int prefixCount(vector& words, string pref) {
    return count_if(begin(words), end(words), [&](const string& w) {
      return w.find(pref) == 0;
    });
  }
};

The post 花花酱 LeetCode 2185. Counting Words With a Given Prefix appeared first on Huahua's Tech Road.

玩转Linux命令行 – 事件处理 – EP3

zxi — Fri, 08 May 2020 07:40:47 +0000

Download Data

download.sh

for i in $(seq -w 01 80)
do  
  curl -O -J https://raw.githubusercontent.com/rozim/ChessData/master/mega2400_part_${i}.pgn
done

V1

cat *.pgn | grep "Result" | sort | uniq -c

V2

cat *.pgn | grep "Result" | awk '{ split($0, a, "-"); res = substr(a[1], length(a[1]), 1); if (res == 1) white++; if (res == 0) black++; if (res == 2) draw++;} END { print white+black+draw, white, black, draw }'

V3

find . -type f -name '*.pgn' -print0 | xargs -0 -n1 -P8 mawk '/Result/ { split($0, a, "-"); res = substr(a[1], length(a[1]), 1); if (res == 1) white++; if (res == 0) black++; if (res == 2) draw++ } END { print white+black+draw, white, black, draw }' | awk '{games += $1; white += $2; black += $3; draw += $4; } END { print games, white, black, draw }'

The post 玩转Linux命令行 – 事件处理 – EP3 appeared first on Huahua's Tech Road.

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花花酱 LeetCode 2185. Counting Words With a Given Prefix

Solution: Straight forward

C++

玩转Linux命令行 – 事件处理 – EP3

Download Data

download.sh

V1

V2

V3