With the help of the backtracking algorithm, I will solve the permutations and subsets problems in Java that are frequently used during job interviews.
suppress automatic printing of pattern space -E, -r, --regexp-extended use extended regular expressions in the script (for portability use POSIX -E). 解法3 awk '/^([0-9]{3}-|\([0-9]{3}\) )[0-9]{3}-[0-9]{4}$/' file.txt 引用和推荐阅读: https://leetcode.com/problems.....
-n, --quiet, --silent suppress automatic printing of pattern space -E, -r, --regexp-extended use extended regular expressions in the script (for portability use POSIX -E). 解法3 awk'/^([0-9]{3}-|\([0-9]{3}\) )[0-9]{3}-[0-9]{4}$/'file.txt https://alid-phone-numbe...
若没有会输出全部 '10p': 中的p指print -n, --quiet, --silent suppress automatic printing of pattern space p Print the current pattern space. number Match only the specified line number (which increments cumula‐ tively across files, unless the -s option is specified on the command line)....
Pattern of the Problem: This problem belongs to the category of cycle detection problems. The pattern involves using two pointers moving at different speeds through the array. The core concept behind the solution is the Floyd’s Tortoise and Hare algorithm for cycle detection. ...
-n, --quiet, --silent suppress automatic printing of pattern space -E,-r,--regexp-extendeduseextended regular expressionsinthescript(forportabilityusePOSIX-E). 解法3 awk '/^([0-9]{3}-|\([0-9]{3}\) )[0-9]{3}-[0-9]{4}$/' file.txt...