[ARTS] punch sixth week

ARTS completed a week

• Do at least a week leetcode algorithm problem

• Read and review at least one technical articles in English

• At least one technical skill learning

• Share ideas and think there is a technical article.

• (That is, Algorithm, Review, Tip, Share short ARTS)

  Algorithm

  76. Minimum Window Substring

  Give you a string S, a string T, please find inside the string S: T contains all the letters of the smallest sub-string.

  string minWindow(string s, string t) {
    if (s.size() < t.size())
    return "";
  
    int szdst[256] = {0};
    int szsub[256] = {0};
  
    for (int i = 0; i < t.size(); i ++)
    {
      szdst[t[i]] ++;
    }
  
    int minlen = s.size() + 1;
  
    int l = 0, r = -1;
    int start = -1;
    int count = 0;
  
    while (l < s.size())
    {
      if (count < t.size() && r + 1 < s.size())
      {
        szsub[s[++r]] ++;
        if (szdst[s[r]] >= szsub[s[r]])
          count ++;
      }
      else
      {
        if (count == t.size())
        {
          if (r - l + 1 < minlen)
          {
            minlen = r - l + 1;
            start = l;
          }
        }
        szsub[s[l]] --;
  
        if (szdst[s[l]] > szsub[s[l]])
          count --;
        l ++;
      }
    }
  
    if (start == -1)
      return "";
    return s.substr(start, minlen);
  }

  Review

  MySQL Big DELETEs

  It describes how to delete lines from a large mysql table data.

  Tip

  How to test Linux IO performance (disk read and write speed)

  1. Test IO read
  hdparm -t --direct / dev / sda3

  IO test can be read using the above command, but this tool hdparm need to install their own, but also the root user to perform.

  2.测试IO写
  sync;/usr/bin/time -p bash -c "(dd if=/dev/zero of=test.dd bs=1000K count=20000;sync)"

  dd bs = 1M count = 20000 if = / dev / zero of = test.dd conv = fdatasync dd IO command to test sequential write and read mode.

  Share

  What Nginx that? Can you do?