basic math book

swap by using the fsck command to divide a partition into a swap, and then use the MKSWAP command to format the partition as swap, and then use the Swapon The device file name "to start the swap device. can use Free This memory view command to see if swap is loaded correctly. In addition to building a partition into swap, you can use a large file to construct the swap, which is similar. you can also use Swapoff to release swap files when you use a file to build swap. This chapter is a summary

Class count{public int Count (String a) {int n = a.length (); int result = 0;int num = 0;int p = 0;int L1 = A.indexof (' ('); int R1 = A.indexof (') '); String B = a.substring (l1+1,r1-1); int op = 0;if (L1 >= 0) return Count (b) + Result;else {for (int i=0; i This bird thing with iteration, in fact, not very good waste of space, more data is also easy to die, someone with a stack has not been studiedThis one's 600mm, and it's not clear.Https://leetcode.com/discuss/39454/accepted-infix-postfix

Section III File operations File attribute Ls–al (the first character of the filename is. for hidden files)Number of connections: How many file names are connected to the secondary node (i-node)Display the full time format: "Ls-l–full-time"File type permissions:-rwxrwx-The first file type: D-directory directory;-Files; l-link file link files; B-accessible random access device; C Serial Port deviceR Readable, W writable, x executable第2-4 for file owner rights, 5-7 for group permissions,