#2977
Minimum Cost to Convert String II
expert · 1215 · lc hard +32 · verified · 59.7% accepted · 380 likes · top 58%
Description
You are given two 0-indexed strings source and target, both of length n, plus two 0-indexed string arrays original and changed, and an integer array cost, where cost[i] is the cost to convert substring original[i] to changed[i].
Starting from source, in one operation pick a substring x and convert it to y at cost z if some index j has cost[j] == z, original[j] == x, changed[j] == y. Any two operations must have either disjoint index ranges or identical index ranges.
Return the minimum cost to convert source to target, or -1 if impossible.
Note: duplicate pairs may appear.
Example 1:
Input: source = "abcd", target = "acbe", original = ["a","b","c","c","e","d"], changed = ["b","c","b","e","b","e"], cost = [2,5,5,1,2,20]
Output: 28
Explanation: To convert "abcd" to "acbe", do the following operations:
- Change substring source[1..1] from "b" to "c" at a cost of 5.
- Change substring source[2..2] from "c" to "e" at a cost of 1.
- Change substring source[2..2] from "e" to "b" at a cost of 2.
- Change substring source[3..3] from "d" to "e" at a cost of 20.
The total cost incurred is 5 + 1 + 2 + 20 = 28.
It can be shown that this is the minimum possible cost.
Example 2:
Input: source = "abcdefgh", target = "acdeeghh", original = ["bcd","fgh","thh"], changed = ["cde","thh","ghh"], cost = [1,3,5]
Output: 9
Explanation: To convert "abcdefgh" to "acdeeghh", do the following operations:
- Change substring source[1..3] from "bcd" to "cde" at a cost of 1.
- Change substring source[5..7] from "fgh" to "thh" at a cost of 3. We can do this operation because indices [5,7] are disjoint with indices picked in the first operation.
- Change substring source[5..7] from "thh" to "ghh" at a cost of 5. We can do this operation because indices [5,7] are disjoint with indices picked in the first operation, and identical with indices picked in the second operation.
The total cost incurred is 1 + 3 + 5 = 9.
It can be shown that this is the minimum possible cost.
Example 3:
Input: source = "abcdefgh", target = "addddddd", original = ["bcd","defgh"], changed = ["ddd","ddddd"], cost = [100,1578]
Output: -1
Explanation: It is impossible to convert "abcdefgh" to "addddddd".
If you select substring source[1..3] as the first operation to change "abcdefgh" to "adddefgh", you cannot select substring source[3..7] as the second operation because it has a common index, 3, with the first operation.
If you select substring source[3..7] as the first operation to change "abcdefgh" to "abcddddd", you cannot select substring source[1..3] as the second operation because it has a common index, 3, with the first operation.
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