程序与算法的专栏

ConstraintsTime Limit: 1 secs, Memory Limit: 32 MBDescriptionAlice and Bob need to send secret messages to each other and are discussing ways to encode their messages: Alice: "Let's just u

Longest Common SubsequenceLongest Common Subsequence （ LCS ），中文可以譯做「最長共同子序列」。它和 LIS 是不一樣的。 LCS 是兩個 sequence ，在各自所有的 subsequence 之中，一模一樣而且最長的那個 subsequence 。s1：2 5 7 9 3 1 2s2：3 5 3 2 8以上例來看， s

1687. PermutationConstraintsTime Limit: 1 secs, Memory Limit: 32 MBDescriptionPermutation plays a very important role in Combinatorics. For example, 1 2 3 4 5 and 1 3 5 4 2 are both 5-perm

Given three strings, you are to determine whether the third string can be formed by combining the characters in the first two strings. The first two strings can be mixed arbitrarily, but each must stay in its original order. For example, consider forming "