{ "data": { "question": { "questionId": "282", "questionFrontendId": "282", "categoryTitle": "Algorithms", "boundTopicId": 1550, "title": "Expression Add Operators", "titleSlug": "expression-add-operators", "content": "

Given a string num that contains only digits and an integer target, return all possibilities to insert the binary operators '+', '-', and/or '*' between the digits of num so that the resultant expression evaluates to the target value.

\n\n

Note that operands in the returned expressions should not contain leading zeros.

\n\n

 

\n

Example 1:

\n\n
\nInput: num = "123", target = 6\nOutput: ["1*2*3","1+2+3"]\nExplanation: Both "1*2*3" and "1+2+3" evaluate to 6.\n
\n\n

Example 2:

\n\n
\nInput: num = "232", target = 8\nOutput: ["2*3+2","2+3*2"]\nExplanation: Both "2*3+2" and "2+3*2" evaluate to 8.\n
\n\n

Example 3:

\n\n
\nInput: num = "3456237490", target = 9191\nOutput: []\nExplanation: There are no expressions that can be created from "3456237490" to evaluate to 9191.\n
\n\n

 

\n

Constraints:

\n\n\n", "translatedTitle": "给表达式添加运算符", "translatedContent": "

给定一个仅包含数字 0-9 的字符串 num 和一个目标值整数 target ，在 num 的数字之间添加 二元 运算符（不是一元）+、- 或 * ，返回 所有 能够得到 target 的表达式。

\n\n

注意，返回表达式中的操作数 不应该 包含前导零。

\n\n

 

\n\n

示例 1:

\n\n
\n输入: num = \"123\", target = 6\n输出: [\"1+2+3\", \"1*2*3\"] \n解释: “1*2*3” 和 “1+2+3” 的值都是6。\n
\n\n

示例 2:

\n\n
\n输入: num = \"232\", target = 8\n输出: [\"2*3+2\", \"2+3*2\"]\n解释: “2*3+2” 和 “2+3*2” 的值都是8。\n
\n\n

示例 3:

\n\n
\n输入: num = \"3456237490\", target = 9191\n输出: []\n解释: 表达式 “3456237490” 无法得到 9191 。\n
\n\n

 

\n\n

提示：

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\r\n1 + 2 - 4 --> 3 - 4 --> -1
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