{ "data": { "question": { "questionId": "1032", "questionFrontendId": "990", "categoryTitle": "Algorithms", "boundTopicId": 2973, "title": "Satisfiability of Equality Equations", "titleSlug": "satisfiability-of-equality-equations", "content": "
You are given an array of strings equations
that represent relationships between variables where each string equations[i]
is of length 4
and takes one of two different forms: "xi==yi"
or "xi!=yi"
.Here, xi
and yi
are lowercase letters (not necessarily different) that represent one-letter variable names.
Return true
if it is possible to assign integers to variable names so as to satisfy all the given equations, or false
otherwise.
\n
Example 1:
\n\n\nInput: equations = ["a==b","b!=a"]\nOutput: false\nExplanation: If we assign say, a = 1 and b = 1, then the first equation is satisfied, but not the second.\nThere is no way to assign the variables to satisfy both equations.\n\n\n
Example 2:
\n\n\nInput: equations = ["b==a","a==b"]\nOutput: true\nExplanation: We could assign a = 1 and b = 1 to satisfy both equations.\n\n\n
\n
Constraints:
\n\n1 <= equations.length <= 500
equations[i].length == 4
equations[i][0]
is a lowercase letter.equations[i][1]
is either '='
or '!'
.equations[i][2]
is '='
.equations[i][3]
is a lowercase letter.给定一个由表示变量之间关系的字符串方程组成的数组,每个字符串方程 equations[i]
的长度为 4
,并采用两种不同的形式之一:"a==b"
或 "a!=b"
。在这里,a 和 b 是小写字母(不一定不同),表示单字母变量名。
只有当可以将整数分配给变量名,以便满足所有给定的方程时才返回 true
,否则返回 false
。
\n\n
示例 1:
\n\n输入:["a==b","b!=a"]\n输出:false\n解释:如果我们指定,a = 1 且 b = 1,那么可以满足第一个方程,但无法满足第二个方程。没有办法分配变量同时满足这两个方程。\n\n\n
示例 2:
\n\n输入:["b==a","a==b"]\n输出:true\n解释:我们可以指定 a = 1 且 b = 1 以满足满足这两个方程。\n\n\n
示例 3:
\n\n输入:["a==b","b==c","a==c"]\n输出:true\n\n\n
示例 4:
\n\n输入:["a==b","b!=c","c==a"]\n输出:false\n\n\n
示例 5:
\n\n输入:["c==c","b==d","x!=z"]\n输出:true\n\n\n
\n\n
提示:
\n\n1 <= equations.length <= 500
equations[i].length == 4
equations[i][0]
和 equations[i][3]
是小写字母equations[i][1]
要么是 '='
,要么是 '!'
equations[i][2]
是 '='
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Python 2.7.12<\\/code><\\/p>\\r\\n\\r\\n
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