找到给定字符串中缺少的括号

Question

我遇到了一个问题，我们必须在给定字符串中找到缺少的花括号。要成为一个有效的字符串，每个左大括号应该有一个右括号。

输入字符串将是这样的（这是有效的）：

    var validInput = 
   `{
       {
         {
         }
       }
    }

    {
    }

    {
      {
      } 
    }`

var invalidInput =
`
{
  {
  }
}

{
//missing a closing brace here

{
}

`

我尝试循环遍历字符串中的每个字符，并且我维护了2个数组，一个用于打开大括号，另一个用于右大括号。我一直在循环中的各个数组中推动括号。有了这个，我可以找出给定的字符串是否有效（如果两个数组的长度相等）。但我无法弄清楚缺失支具的位置或索引。请告诉我如何实现这一目标。

参考代码： https://jsfiddle.net/Lzqodfk4/1/

Answer 1

由于不考虑空格，这根本不可能。举个例子

feats.model

是缺少的第三个或最后一个括号？你无法真正说出来。但是，在这个例子中，“恢复”这种支撑的结果将是相同的：

svm_type epsilon_svr
kernel_type rbf
gamma 0.5
nr_class 2
total_sv 97
rho -0.333511
probA 0.161783
SV
0.003704278553649198 1:0.510292 2:0.192089 3:0.513893 4:0.548984 5:0.614196 6:0.422312 7:0.756692 8:0.243308 9:0.314877 10:0.286878 11:0.143726 12:0.169265 13:0.322193 14:0.446887 15:0.340164 16:0.239344 17:0.238347 18:0.373818 19:0.579746 20:0.336459 21:0.175325 22:0.0925373 23:0.322247 24:0.446311 25:0.416496 26:0.225 27:0.2 28:0.441021 29:0.341773 30:0.340589 31:0.15414 32:0.162791 33:0.400171 
-0.5 1:0.239529 2:0.509408 3:0.194768 4:0.140251 5:0.323725 6:0.282628 7:0.501399 8:0.498601 9:0.264498 10:0.249288 11:0.320659 12:0.315038 13:0.349058 14:0.485075 15:0.466071 16:0.460838 17:0.559229 18:0.604843 19:0.684191 20:0.591079 21:0.61039 22:0.46932 23:0.662154 24:0.353571 25:0.310211 26:0.295455 27:0.246914 28:0.358677 29:0.512774 30:0.236713 31:0.422505 32:0.276486 33:0.342528 34:0.302198 35:0.190476 38:0.370879 39:0.444444 
0.1394560286546107 1:0.155169 2:0.24953 3:0.139667 4:0.220046 5:0.162154 6:0.161413 7:0.42755 8:0.57245 9:0.169278 10:0.116145 11:0.1225 12:0.126426 13:0.221127 14:0.460867 15:0.540366 16:0.28154 17:0.408983 18:0.790225 19:0.581336 20:0.4428 21:0.238848 22:0.179753 23:0.570333 24:0.599045 25:0.575372 26:0.337945 27:0.309179 28:0.722944 29:0.219931 30:0.187145 31:0.144835 32:0.12639 33:0.338516 
-0.2177410947329247 1:0.407746 2:0.77446 3:0.370246 4:0.478536 5:0.363025 6:0.424849 7:0.392069 8:0.607931 9:0.306265 10:0.369993 11:0.516818 12:0.551465 13:0.429111 14:0.546025 15:0.533429 16:0.697352 17:0.853528 18:0.617085 19:0.381296 20:0.421772 21:0.584416 22:0.522388 23:0.407158 24:0.282857 25:0.322619 26:0.314685 27:0.34188 28:0.341095 29:0.831686 30:0.388049 31:0.819696 32:0.542039 33:0.453437 
0.07172083700103118 1:0.343284 2:0.567237 3:0.355343 4:0.320906 5:0.317058 6:0.486173 7:0.462343 8:0.537657 9:0.146061 10:0.297108 11:0.280368 12:0.376972 13:0.302624 14:0.552922 15:0.575728 16:0.55824 17:0.721618 18:0.637894 19:0.405324 20:0.407375 21:0.42447 22:0.371563 23:0.367107 24:0.913107 25:0.90443 26:0.818182 27:0.77193 28:0.922189 29:0.291093 30:0.00557018 31:0.340261 32:0.138311 34:0.400485 35:0.270677 42:1 43:0.868421 
-0.3094983056964442 1:0.436071 2:0.978574 3:0.498165 4:0.433746 5:0.249021 6:0.155329 7:0.264944 8:0.735056 9:0.0751117 10:0.00664228 11:0.429658 12:0.306257 13:0.0542717 14:0.534434 15:0.432468 16:0.825137 17:0.867769 18:0.632014 19:0.536559 20:0.440424 21:0.974026 22:0.681592 23:0.571392 24:0.54 25:0.58658 26:0.715909 27:0.740741 28:0.740248 29:0.643238 30:0.146672 31:0.847134 32:0.410853 33:0.286256 34:1 35:1 36:1 37:1 42:0.35671 43:0.458333 
-0.2127153117962579 1:0.29474 2:0.686222 3:0.277662 4:0.372119 5:0.0999395 6:0.104283 7:0.313798 8:0.686202 9:0.259288 10:0.13645 11:0.425563 12:0.316389 13:0.28685 14:0.269281 15:0.269159 16:0.354351 17:0.4548 18:0.409764 19:0.610769 20:0.548504 21:0.746254 22:0.577497 23:0.740365 24:0.339252 25:0.316589 26:0.346154 27:0.307692 28:0.414735 29:0.127795 30:0.0708427 31:0.302303 32:0.227191 33:0.204197 34:0.17134 35:0.131868 38:0.21028 39:0.307692 
-0.2496431871080472 1:0.510205 2:0.553358 3:0.461522 4:0.47673 5:0.435839 6:0.507867 7:0.625846 8:0.374154 9:0.285986 10:0.372825 11:0.361217 12:0.420417 13:0.385917 14:0.536158 15:0.550781 16:0.533698 17:0.682645 18:0.596873 19:0.539105 20:0.527372 21:0.532468 22:0.456053 23:0.473571 24:0.721875 25:0.676324 26:0.636364 27:0.567901 28:0.681028 29:0.352442 30:0.14796 31:0.365888 32:0.235142 33:0.150792 34:0.572917 35:0.380952 36:0.501302 37:0.333333 38:0.175781 39:0.222222 
-0.5 1:0.39885 2:0.558632 3:0.433279 4:0.549147 5:0.451879 6:0.436535 7:0.618319 8:0.381681 9:0.371905 10:0.38368 11:0.419011 12:0.430955 13:0.439957 14:0.40664 15:0.3375 16:0.422951 17:0.460496 18:0.365202 19:0.64188 20:0.667498 21:0.631169 22:0.570149 23:0.647734 24:0.215217 25:0.245471 26:0.190909 27:0.207407 28:0.257716 29:0.351007 31:0.368153 32:0.131783 33:0.00525235 
-0.128526024769383 1:0.370543 2:0.830243 3:0.374009 4:0.420573 5:0.336729 6:0.339568 7:0.566359 8:0.433641 9:0.422597 10:0.32342 11:0.65019 12:0.543359 13:0.418273 14:0.322087 15:0.311691 16:0.47541 17:0.590083 18:0.368456 19:0.535713 20:0.635179 21:0.818182 22:0.781095 23:0.673289 24:0.378529 25:0.398529 26:0.443182 27:0.444444 28:0.444149 29:0.706362 30:0.409689 31:0.779193 32:0.596899 33:0.525309 34:0.323529 35:0.285714 38:0.198529 39:0.333333 42:0.403922 43:0.458333 
-0.5 1:0.336929 2:0.619283 3:0.402381 4:0.461545 5:0.294114 6:0.560478 7:0.475044 8:0.524956 9:0.381502 10:0.487365 11:0.467681 12:0.543359 13:0.496372 14:0.241649 15:0.202083 16:0.300546 17:0.343251 18:0.164813 19:0.621826 20:0.616812 21:0.681818 22:0.58209 23:0.533444 24:0.394565 25:0.327295 26:0.375 27:0.296296 28:0.319923 29:0.413596 30:0.260786 31:0.43949 32:0.348837 33:0.254657 
-0.1284103133236481 1:0.522824 2:0.869798 3:0.583767 4:0.547795 5:0.508961 6:0.307428 7:0.736016 8:0.263984 9:0.459364 10:0.375196 11:0.711027 12:0.613611 13:0.511041 14:0.379192 15:0.246402 16:0.562842 17:0.51809 18:0.292481 19:0.649172 20:0.510371 21:1 22:0.681592 23:0.558851 24:0.525 25:0.384943 26:0.636364 27:0.444444 28:0.437937 29:0.579549 30:0.288445 31:0.716914 32:0.503876 33:0.394638 34:0.416667 35:0.380952 36:0.486111 37:0.444444 
-0.5 1:0.413909 2:0.526046 3:0.450952 4:0.458142 5:0.559618 6:0.469773 7:0.755839 8:0.244161 9:0.649274 10:0.459739 11:0.565454 12:0.460561 13:0.517085 14:0.269144 15:0.289706 16:0.288056 17:0.391736 18:0.294484 19:0.593168 20:0.688264 21:0.55102 22:0.556503 23:0.64914 24:0.0685121 25:0.078143 26:0.0584416 27:0.0634921 28:0.0804432 29:0.509709 30:0.272155 31:0.432211 32:0.30897 33:0.301686 34:0.190311 35:0.122449 38:0.233564 39:0.285714 
0.04821612562570891 1:0.367215 2:0.676818 3:0.433176 4:0.476298 5:0.417112 6:0.437687 7:0.477799 8:0.522201 9:0.405974 10:0.447972 11:0.525752 12:0.552939 13:0.52237 14:0.583064 15:0.322398 16:0.66617 17:0.51435 18:0.345844 19:0.361426 20:0.519472 21:0.478158 22:0.544098 23:0.499161 24:0.220818 25:0.251859 26:0.22314 27:0.242424 28:0.264241 29:0.528581 30:0.193376 31:0.546034 32:0.323467 33:0.225232 
0.5 1:0.401844 2:0.995056 3:0.517845 4:0.385894 5:0.50683 6:1 7:0.66892 8:0.33108 9:0.439376 10:0.64369 11:0.787072 12:0.964874 13:0.441535 14:0.362473 15:0.31 16:0.606557 17:0.682645 18:0.185287 19:0.495642 20:0.69869 21:0.935065 22:1 23:0.425939 24:0.152308 25:0.173718 26:0.204545 27:0.222222 28:0.136438 29:0.441905 30:0.341295 31:0.694268 32:0.627907 33:0.196415 
-0.1337953485189151 1:0.58915 2:0.747076 3:0.590697 4:0.550136 5:0.638569 6:0.435263 7:0.770819 8:0.229181 9:0.637202 10:0.566117 11:0.755484 12:0.697374 13:0.676848 14:0.657292 15:0.617229 16:0.798235 17:0.93897 18:0.716938 19:0.208225 20:0.287813 21:0.368631 22:0.375431 23:0.268554 24:0.319355 25:0.298021 26:0.346154 27:0.307692 28:0.313125 29:0.277149 30:0.111962 31:0.427732 32:0.284436 33:0.133262 34:0.322581 35:0.263736 38:0.395894 39:0.615385 

然而，这里有一个例子，你不仅不知道支架丢失的位置，还有不同的方法来恢复它：

{{}

可能会变成

{{}}

或

{{}{{}}

发生这种情况时？是否有一些非平凡的情况，你仍然能够恢复支具（这比找到它的原始位置少）？

实际上，当你猜测丢失支撑的位置时，唯一限制你的是 - 在每个位置之前你不能有更多的关闭括号。所以恢复可以肯定的唯一情况是，当你有一个没有破坏的序列，然后是一些开口大括号，然后关闭大括号（少了1个）时：

{{}}{{}}

如果从{{}{{}}} 开始，将任何重要内容放入序列中，例如

{}{}{{}}{{{{ }}}
        *   ^^^^ put it on any of these positions

或

*

恢复是不明确的。

换句话说，如果有点

{{}{{{ }}}

你可能确定问题是在前面，而不是落后（如果缺少关闭问题），但仅此而已。