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55 lines
3.3 KiB
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55 lines
3.3 KiB
HTML
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<p>给定一个变量对数组 <code>equations</code> 和一个实数值数组 <code>values</code> 作为已知条件，其中 <code>equations[i] = [A<sub>i</sub>, B<sub>i</sub>]</code> 和 <code>values[i]</code> 共同表示等式 <code>A<sub>i</sub> / B<sub>i</sub> = values[i]</code> 。每个 <code>A<sub>i</sub></code> 或 <code>B<sub>i</sub></code> 是一个表示单个变量的字符串。</p>
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<p>另有一些以数组 <code>queries</code> 表示的问题，其中 <code>queries[j] = [C<sub>j</sub>, D<sub>j</sub>]</code> 表示第 <code>j</code> 个问题，请你根据已知条件找出 <code>C<sub>j</sub> / D<sub>j</sub> = ?</code> 的结果作为答案。</p>
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<p>返回 <strong>所有问题的答案</strong> 。如果存在某个无法确定的答案，则用 <code>-1.0</code> 替代这个答案。如果问题中出现了给定的已知条件中没有出现的字符串，也需要用 <code>-1.0</code> 替代这个答案。</p>
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<p><strong>注意：</strong>输入总是有效的。可以假设除法运算中不会出现除数为 0 的情况，且不存在任何矛盾的结果。</p>
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<p> </p>
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<p><strong>示例 1：</strong></p>
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<pre>
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<strong>输入：</strong>equations = [["a","b"],["b","c"]], values = [2.0,3.0], queries = [["a","c"],["b","a"],["a","e"],["a","a"],["x","x"]]
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<strong>输出：</strong>[6.00000,0.50000,-1.00000,1.00000,-1.00000]
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<strong>解释：</strong>
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条件：<em>a / b = 2.0</em>, <em>b / c = 3.0</em>
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问题：<em>a / c = ?</em>, <em>b / a = ?</em>, <em>a / e = ?</em>, <em>a / a = ?</em>, <em>x / x = ?</em>
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结果：[6.0, 0.5, -1.0, 1.0, -1.0 ]
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</pre>
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<p><strong>示例 2：</strong></p>
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<pre>
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<strong>输入：</strong>equations = [["a","b"],["b","c"],["bc","cd"]], values = [1.5,2.5,5.0], queries = [["a","c"],["c","b"],["bc","cd"],["cd","bc"]]
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<strong>输出：</strong>[3.75000,0.40000,5.00000,0.20000]
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</pre>
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<p><strong>示例 3：</strong></p>
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<pre>
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<strong>输入：</strong>equations = [["a","b"]], values = [0.5], queries = [["a","b"],["b","a"],["a","c"],["x","y"]]
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<strong>输出：</strong>[0.50000,2.00000,-1.00000,-1.00000]
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</pre>
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<p> </p>
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<p><strong>提示：</strong></p>
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<ul>
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<li><code>1 <= equations.length <= 20</code></li>
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<li><code>equations[i].length == 2</code></li>
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<li><code>1 <= A<sub>i</sub>.length, B<sub>i</sub>.length <= 5</code></li>
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<li><code>values.length == equations.length</code></li>
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<li><code>0.0 < values[i] <= 20.0</code></li>
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<li><code>1 <= queries.length <= 20</code></li>
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<li><code>queries[i].length == 2</code></li>
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<li><code>1 <= C<sub>j</sub>.length, D<sub>j</sub>.length <= 5</code></li>
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<li><code>A<sub>i</sub>, B<sub>i</sub>, C<sub>j</sub>, D<sub>j</sub></code> 由小写英文字母与数字组成</li>
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</ul>
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<p> </p>
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<p><meta charset="UTF-8" />注意：本题与主站 399 题相同： <a href="https://leetcode-cn.com/problems/evaluate-division/">https://leetcode-cn.com/problems/evaluate-division/</a></p>
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