本文介绍了n对括号的所有有效组合的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！
问题描述
- 我正在学习js ..
- 我正在尝试编写一个简单的js程序..
- 我要做的是打印n对括号的所有有效组合（正确打开和关闭）
- 例如（），（（）（ ）），（（））
- 我写的逻辑可以告诉我它是否正确
- I am learning js now..
- I am trying to write a simple js programme..
- what I am trying to do is to print all valid combinations of n-pair of parenthesis(properly opened and closed)
- eg (), (()()),(())
- i have written the logic can you tell me whether its correct or not
jsfiddle/e7mcp6xb/
module.exports = Parentheses = (function() { var _isParenthesesMatch = function(str) { var parentheses = str.length; var rightParentheses = '('; var leftParentheses = ')'; var rightCount = 0; var leftCount = 0; for(i=0;i<=str.length;i++){ if(rightParentheses == str.charAt(i)) { rightCount++; } else if(leftParentheses == str.charAt(i)) { leftCount++; } } if(rightCount == leftCount){ return true; } else(rightCount != leftCount){ return false; } } }());
推荐答案检查错误，但您可以轻松修复：在 for 循环的每一步中，左括号的数量不能小于结束数量：
The check is wrong, but You can fix it easily: In each step of the for loop the number of opening parenthesis cannot be smaller than the number of closing ones:
if (rightCount < leftCount) return false;整个函数应如下所示：
function(str) { var rightParentheses = '('; var leftParentheses = ')'; var rightCount = 0; var leftCount = 0; for (var i = 0; i <= str.length; i++) { if (rightParentheses == str.charAt(i)) rightCount++; else if (leftParentheses == str.charAt(i)) leftCount++; if (rightCount < leftCount) return false; } return rightCount == leftCount; }如果您想生成所有有效字符串，可以使用此功能：
If You'd like to generate all valid strings, you can use this function:
function nPair(n) { if (n == 0) return [""]; var result = []; for (var i = 0; i < n; ++i) { var lefts = nPair(i); var rights = nPair(n - i - 1); for (var l = 0; l < lefts.length; ++l) for (var r = 0; r < rights.length; ++r) result.push("(" + lefts[l] + ")" + rights[r]); } return result; } // result of nPair(3): // ["()()()", "()(())", "(())()", "(()())", "((()))"]
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n对括号的所有有效组合
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