为什么大家那么快就收到了ead和ap# Immigration - 落地生根
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Given 3 strings of only lowercase letter you have to count the number of
ways you can construct the third string by combining two subsequences from
the first two strings.
After deleting 0 or more characters from a string we can get its subsequence
. For example “a”, “b”, “c”, “ab”, “ac”, “bc” and “abc” all
the strings are the subsequences of “abc”. A subsequence may also be empty.
Now suppose there are two subsequences “abc” and “de”. By combining them
you can get the following strings “abcde”, “abdce”, “abdec”, “adbce
”, “adbec”, “adebc”, “dabce”, “dabec”, “daebc” and “deabc”.
ways you can construct the third string by combining two subsequences from
the first two strings.
After deleting 0 or more characters from a string we can get its subsequence
. For example “a”, “b”, “c”, “ab”, “ac”, “bc” and “abc” all
the strings are the subsequences of “abc”. A subsequence may also be empty.
Now suppose there are two subsequences “abc” and “de”. By combining them
you can get the following strings “abcde”, “abdce”, “abdec”, “adbce
”, “adbec”, “adebc”, “dabce”, “dabec”, “daebc” and “deabc”.