Package g2901_3000.s2976_minimum_cost_to_convert_string_i

Class Solution

java.lang.Object
g2901_3000.s2976_minimum_cost_to_convert_string_i.Solution
public class Solution extends java.lang.Object
2976 - Minimum Cost to Convert String I.

Medium

You are given two 0-indexed strings source and target, both of length n and consisting of lowercase English letters. You are also given two 0-indexed character arrays original and changed, and an integer array cost, where cost[i] represents the cost of changing the character original[i] to the character changed[i].

You start with the string source. In one operation, you can pick a character x from the string and change it to the character y at a cost of z if there exists any index j such that cost[j] == z, original[j] == x, and changed[j] == y.

Return the minimum cost to convert the string source to the string target using any number of operations. If it is impossible to convert source to target, return -1.

Note that there may exist indices i, j such that original[j] == original[i] and changed[j] == changed[i].

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 the string “abcd” to string “acbe”:

  • Change value at index 1 from ‘b’ to ‘c’ at a cost of 5.
  • Change value at index 2 from ‘c’ to ‘e’ at a cost of 1.
  • Change value at index 2 from ‘e’ to ‘b’ at a cost of 2.
  • Change value at index 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 = “aaaa”, target = “bbbb”, original = [“a”,“c”], changed = [“c”,“b”], cost = [1,2]

Output: 12

Explanation: To change the character ‘a’ to ‘b’ change the character ‘a’ to ‘c’ at a cost of 1, followed by changing the character ‘c’ to ‘b’ at a cost of 2, for a total cost of 1 + 2 = 3. To change all occurrences of ‘a’ to ‘b’, a total cost of 3 * 4 = 12 is incurred.

Example 3:

Input: source = “abcd”, target = “abce”, original = [“a”], changed = [“e”], cost = [10000]

Output: -1

Explanation: It is impossible to convert source to target because the value at index 3 cannot be changed from ‘d’ to ‘e’.

Constraints:

  • 1 <= source.length == target.length <= 105
  • source, target consist of lowercase English letters.
  • 1 <= cost.length == original.length == changed.length <= 2000
  • original[i], changed[i] are lowercase English letters.
  • 1 <= cost[i] <= 106
  • original[i] != changed[i]

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    long
    minimumCost(java.lang.String inputText, java.lang.String desiredText, char[] fromLetters, char[] toLetters, int[] transformationCost)
     

    Methods inherited from class java.lang.Object

    clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

  • Constructor Details

    • Solution

      public Solution()

  • Method Details

    • minimumCost

      public long minimumCost(java.lang.String inputText, java.lang.String desiredText, char[] fromLetters, char[] toLetters, int[] transformationCost)