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func largestMerge(s, t string) string {

    n := len(s)

    sa := *(*[]int32)(unsafe.Pointer(reflect.ValueOf(suffixarray.New([]byte(s + "#" + t))).Elem().FieldByName("sa").Field(0).UnsafeAddr()))

    rank := make([]int, n+1+len(t))

    for i := range rank {

        rank[sa[i]] = i

    }

    ans := []byte{}

    i, j := 0, n+1

    for {

        if s == "" {

            ans = append(ans, t...)

            break

        }

        if t == "" {

            ans = append(ans, s...)

            break

        }

        if rank[i] > rank[j] { // s > t

            ans = append(ans, s[0])

            s = s[1:]

            i++

        } else {

            ans = append(ans, t[0])

            t = t[1:]

            j++

        }

    }

    return string(ans)

} 

 

1754. Largest Merge Of Two Strings

You are given two strings word1 and word2. You want to construct a string merge in the following way: while either word1 or word2 are non-empty, choose one of the following options:

If word1 is non-empty, append the first character in word1 to merge and delete it from word1.

For example, if word1 = "abc" and merge = "dv", then after choosing this operation, word1 = "bc" and merge = "dva".

If word2 is non-empty, append the first character in word2 to merge and delete it from word2.

For example, if word2 = "abc" and merge = "", then after choosing this operation, word2 = "bc" and merge = "a".

Return the lexicographically largest merge you can construct.

A string a is lexicographically larger than a string b (of the same length) if in the first position where a and b differ, a has a character strictly larger than the corresponding character in b. For example, "abcd" is lexicographically larger than "abcc" because the first position they differ is at the fourth character, and d is greater than c.

Example 1:

Input: word1 = "cabaa", word2 = "bcaaa"

Output: "cbcabaaaaa"

Explanation: One way to get the lexicographically largest merge is:

- Take from word1: merge = "c", word1 = "abaa", word2 = "bcaaa"

- Take from word2: merge = "cb", word1 = "abaa", word2 = "caaa"

- Take from word2: merge = "cbc", word1 = "abaa", word2 = "aaa"

- Take from word1: merge = "cbca", word1 = "baa", word2 = "aaa"

- Take from word1: merge = "cbcab", word1 = "aa", word2 = "aaa"

- Append the remaining 5 a's from word1 and word2 at the end of merge.

Example 2:

Input: word1 = "abcabc", word2 = "abdcaba"

Output: "abdcabcabcaba"

Constraints:

1 <= word1.length, word2.length <= 3000

word1 and word2 consist only of lowercase English letters.

1754. 构造字典序最大的合并字符串 https://leetcode.cn/problems/largest-merge-of-two-strings/

 

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