Package g0301_0400.s0399_evaluate_division

Class Solution

java.lang.Object
g0301_0400.s0399_evaluate_division.Solution
public class Solution extends java.lang.Object
399 - Evaluate Division.

Medium

You are given an array of variable pairs equations and an array of real numbers values, where equations[i] = [Ai, Bi] and values[i] represent the equation Ai / Bi = values[i]. Each Ai or Bi is a string that represents a single variable.

You are also given some queries, where queries[j] = [Cj, Dj] represents the jth query where you must find the answer for Cj / Dj = ?.

Return the answers to all queries. If a single answer cannot be determined, return -1.0.

Note: The input is always valid. You may assume that evaluating the queries will not result in division by zero and that there is no contradiction.

Example 1:

Input: equations = [[“a”,“b”],[“b”,“c”]], values = [2.0,3.0], queries = [[“a”,“c”],[“b”,“a”],[“a”,“e”],[“a”,“a”],[“x”,“x”]]

Output: [6.00000,0.50000,-1.00000,1.00000,-1.00000]

Explanation:

Given: a / b = 2.0, b / c = 3.0

queries are: a / c = ?, b / a = ?, a / e = ?, a / a = ?, x / x = ?

return: [6.0, 0.5, -1.0, 1.0, -1.0 ]

Example 2:

Input: equations = [[“a”,“b”],[“b”,“c”],[“bc”,“cd”]], values = [1.5,2.5,5.0], queries = [[“a”,“c”],[“c”,“b”],[“bc”,“cd”],[“cd”,“bc”]]

Output: [3.75000,0.40000,5.00000,0.20000]

Example 3:

Input: equations = [[“a”,“b”]], values = [0.5], queries = [[“a”,“b”],[“b”,“a”],[“a”,“c”],[“x”,“y”]]

Output: [0.50000,2.00000,-1.00000,-1.00000]

Constraints:

  • 1 <= equations.length <= 20
  • equations[i].length == 2
  • 1 <= Ai.length, Bi.length <= 5
  • values.length == equations.length
  • 0.0 < values[i] <= 20.0
  • 1 <= queries.length <= 20
  • queries[i].length == 2
  • 1 <= Cj.length, Dj.length <= 5
  • Ai, Bi, Cj, Dj consist of lower case English letters and digits.

  • Constructor Summary

    Constructors
    Constructor
    Description
    Solution()
     

  • Method Summary

    Modifier and Type
    Method
    Description
    double[]
    calcEquation(java.util.List<java.util.List<java.lang.String>> equations, double[] values, java.util.List<java.util.List<java.lang.String>> queries)
     

    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

    • calcEquation

      public double[] calcEquation(java.util.List<java.util.List<java.lang.String>> equations, double[] values, java.util.List<java.util.List<java.lang.String>> queries)