0990-satisfiability-of-equality-equations.adoc

990. Satisfiability of Equality Equations

{leetcode}/problems/satisfiability-of-equality-equations/[LeetCode - Satisfiability of Equality Equations^]

Given an array <font face="monospace">equations of strings that represent relationships between variables, each string equations[i] has length 4 and takes one of two different forms: "a==b" or "a!=b". Here, a and b are lowercase letters (not necessarily different) that represent one-letter variable names.

Return true if and only if it is possible to assign integers to variable names so as to satisfy all the given equations.

Example 1:

Input: ["a==b","b!=a"]
Output: false
Explanation: If we assign say, a = 1 and b = 1, then the first equation is satisfied, but not the second.  There is no way to assign the variables to satisfy both equations.

Example 2:

Input: ["b==a","a==b"]
Output: true
Explanation: We could assign a = 1 and b = 1 to satisfy both equations.

Example 3:

Input: ["a==b","b==c","a==c"]
Output: true

Example 4:

Input: ["a==b","b!=c","c==a"]
Output: false

Example 5:

Input: ["c==c","b==d","x!=z"]
Output: true

Note:

1. 1 ⇐ equations.length ⇐ 500

2. equations[i].length == 4

3. equations[i][0] and equations[i][3] are lowercase letters

4. equations[i][1] is either '=' or '!'

5. equations[i][2] is '='

link:{sourcedir}/_0990_SatisfiabilityOfEqualityEquations.java[role=include]