{"id":12199,"date":"2026-04-14T23:50:53","date_gmt":"2026-04-14T18:20:53","guid":{"rendered":"https:\/\/namastedev.com\/blog\/?p=12199"},"modified":"2026-04-15T11:52:35","modified_gmt":"2026-04-15T06:22:35","slug":"minimum-add-to-make-parenthesis-valid","status":"publish","type":"post","link":"https:\/\/namastedev.com\/blog\/minimum-add-to-make-parenthesis-valid\/","title":{"rendered":"Minimum Add to Make Parenthesis Valid"},"content":{"rendered":"\n<link\n    href=\"https:\/\/cdn.jsdelivr.net\/npm\/prismjs@1.29.0\/themes\/prism-tomorrow.min.css\"\n    rel=\"stylesheet\"\n\/>\n<script src=\"https:\/\/cdn.jsdelivr.net\/npm\/prismjs@1.29.0\/prism.min.js\"><\/script>\n<script src=\"https:\/\/cdn.jsdelivr.net\/npm\/prismjs@1.29.0\/plugins\/autoloader\/prism-autoloader.min.js\"><\/script>\n\n<style>\n.wp_blog_theme {\n  --primary: #E58C32;\n  --secondary: #030302;\n  --light-bg: #fef9f4;\n  --text-dark: #2d2d2d;\n  --tab-radius: 12px;\n  --shadow: 0 4px 12px rgba(0, 0, 0, 0.08);\n  --code-bg: #001f3f;\n  --code-text: #d4f1ff;\n}\n\n.wp_blog_container {\n  font-family: 'Segoe UI', sans-serif;\n  background: var(--light-bg);\n  margin: 0;\n  padding: 0;\n  color: var(--text-dark);\n}\n\n\/* Heading *\/\n.wp_blog_main-heading {\n  text-align: center;\n  font-size: 2.4rem;\n  color: var(--primary);\n  margin-top: 2.5rem;\n  font-weight: bold;\n}\n\n\/* Explanation Card *\/\n.wp_blog_explanation,\n.wp_blog_code-tabs-container {\n  max-width: 940px;\n  margin: 2rem auto;\n  padding: 2rem;\n  background: white;\n  border-radius: var(--tab-radius);\n  box-shadow: var(--shadow);\n}\n\n\/* Text and Visuals *\/\n.wp_blog_explanation h2 {\n  font-size: 1.4rem;\n  color: var(--primary);\n  margin-bottom: 0.5rem;\n}\n\n.wp_blog_explanation p,\n.wp_blog_explanation li {\n  font-size: 1.05rem;\n  line-height: 1.7;\n  margin: 0.5rem 0;\n}\n\n.wp_blog_explanation code {\n  background: #fef9f4;   \/* light bg instead of dark blue *\/\n  color: #E58C32;        \/* brand orange *\/\n  padding: 3px 6px;\n  border-radius: 4px;\n  font-family: 'Courier New', monospace;\n  font-weight: 600;      \/* optional, makes it pop *\/\n}\n\n.wp_blog_explanation img {\n  max-width: 100%;\n  border-radius: var(--tab-radius);\n  margin-top: 1rem;\n  box-shadow: 0 2px 12px rgba(0, 0, 0, 0.06);\n}\n\n\/* Tab Buttons *\/\n.wp_blog_code-tabs-header {\n  display: flex;\n  flex-wrap: wrap;\n  gap: 0.5rem;\n  margin-bottom: 1rem;\n}\n\n.wp_blog_code-tab-button {\n  padding: 0.6rem 1.2rem;\n  border: 1px solid var(--primary);\n  background: white;\n  color: var(--primary);\n  border-radius: 50px;\n  font-weight: 600;\n  cursor: pointer;\n  transition: all 0.3s ease;\n}\n\n.wp_blog_code-tab-button:hover {\n  background: var(--secondary);\n}\n\n.wp_blog_code-tab-button.active {\n  background: var(--primary);\n  color: white;\n}\n\n\/* Code Content *\/\n.wp_blog_code-tab-content {\n  display: none;\n  background: var(--code-bg);\n  border-radius: var(--tab-radius);\n}\n\n.wp_blog_code-tab-content.active {\n  display: block;\n}\n\n.wp_blog_code-tab-content pre {\n  margin: 0;\n  padding: 1.5rem;\n  font-size: 1rem;\n  overflow-x: auto;\n  background: var(--code-bg);\n  border-radius: var(--tab-radius);\n  color: var(--code-text);\n}\n\n\/* Dark mode variables *\/\n.wp_blog_theme.dark-mode {\n  --light-bg: #121212;\n  --text-dark: #f5f5f5;\n  --shadow: 0 4px 12px rgba(255, 255, 255, 0.08);\n  --code-bg: #1e1e1e;\n  --code-text: #c5f0ff;\n}\n\n.wp_blog_theme.dark-mode .wp_blog_explanation {\n  background: #1e1e1e;\n}\n\n\/* Dark mode code highlight *\/\n.wp_blog_theme.dark-mode .wp_blog_explanation code {\n  background: #333;\n  color: #ffd27f;\n}\n\n.wp_blog_theme {\n  position: relative; \/* makes it the reference for absolute children *\/\n}\n\n.wp_blog_toggle-btn {\n  position: absolute;\n  top: 1rem;\n  right: 1rem;\n  z-index: 9999;\n  padding: 0.5rem 0.8rem;\n  border-radius: 10%;\n  background: var(--primary);\n  color: white;\n  font-weight: bold;\n  cursor: pointer;\n  border: none;\n  box-shadow: var(--shadow);\n  transition: background 0.3s, transform 0.2s;\n}\n\n.wp_blog_toggle-btn:hover {\n  background: #cc772e;\n}\n\n.wp_blog_theme.dark-mode .wp_blog_code-tabs-container {\n  background: #1e1e1e;\n}\n<\/style>\n\n<div class=\"wp_blog_container wp_blog_theme\"> \n      <button id=\"blogNotesThemeToggle\" class=\"wp_blog_toggle-btn\">\ud83c\udf19<\/button>\n    <h1 class=\"wp_blog_main-heading\"><\/h1>\n    <div class=\"wp_blog_explanation\">\n        <h2>Problem Statement:<\/h2>\n        <p>\n            A <strong>parentheses string <\/strong>is valid if and only if:\n        <\/p>\n        <ul>\n            <li>It is the <strong>empty string<\/strong>,<\/li>\n            <li>It can be written <code>as AB<\/code> (A concatenated with B), where A and B are valid strings, or<\/li>\n            <li>It can be written as (A), where A is a valid string.<\/li>\n            <p>You are <strong>given a parentheses string s<\/strong>. In one move, you can insert a parenthesis at any position of the string.<\/p>\n            <li>For example, if s = &#8220;()))&#8221;, you can insert an opening parenthesis to be &#8220;(()))&#8221; or a closing parenthesis to be &#8220;())))&#8221;.<\/li>\n        <\/ul>\n<strong>\n        <p>Return <i>the minimum<\/i> number of moves required to make <code>s<\/code> valid.<\/p><\/strong>\n\n                <h2>Examples:<\/h2>\n\n                <h3>Example 1:<\/h3>\n                <p><strong>Input:<\/strong> s = &#8220;())&#8221;\n                <\/p>\n                <p><strong>Output:<\/strong> 1<\/p>\n                <!-- <p>\n                  <code>Explanation:<\/code>\n                  Drop the egg from floor 1. If it breaks, we know that f = 0.\n                    Otherwise, drop the egg from floor 2. If it breaks, we know that f = 1.\n                    If it does not break, then we know f = 2.\n                    Hence, we need at minimum 2 moves to determine with certainty what the value of f is.\n                <\/p> -->\n\n\n                <h3>Example 2:<\/h3>\n                <p><strong>Input:<\/strong>  s = &#8220;(((&#8220;<\/p>\n\n                <p><strong>Output:<\/strong> 3<\/p>\n<!-- \n                <h3>Example 3:<\/h3>\n                <p><strong>Input:<\/strong>  k = 3, n = 14<\/p>\n\n                <p><strong>Output:<\/strong> 4<\/p> -->\n        \n\n                <!-- <h5>Example 3:<\/h5>\n                <p><strong>Input:<\/strong>\n                <\/p>\n                <p>\n                    nums1 = [0], m = 0\n                    nums2 = [1], n = 1\n                <\/p>    \n                <p><strong>Output:<\/strong>[1]<\/p>\n                  <p>\n                  <code>Explanation:<\/code>\n                 The arrays we are merging are [] and [1].\n                    The result of the merge is [1].\n                    Note that because m = 0, there are no elements in nums1. \n                    The 0 is only there to ensure the merge result can fit in nums1.\n                <\/p> -->\n\n                <h2>Constraints<\/h2>\n                <p><code>1 <= s.length <= 1000<\/code><\/p>\n                <p><code>\n                  s[i] is either '(' or ')'.\n                <\/code><\/p>\n\n                    <h2>Time Complexity:<\/h2>\n                    <li>\n                      <p><strong>Time Complexity = O(n)<\/strong>\n                      <\/li>\n                    <h2>Space Complexity:<\/h2>\n                    <li>\n                      <p><strong>Space Complexity = O(1)<\/strong><\/p>\n                    <\/li>\n\n                <h2>Approach<\/h2>\n                <ul>\n                    <li>Use two variables:\n                        <ul>\n                            <li><code>openCount<\/code> \u2192 tracks unmatched <code>'('<\/code><\/li>\n                            <li><code>moves<\/code> \u2192 tracks extra <code>')'<\/code> that need fixing<\/li>\n                        <\/ul>\n                        <ul>Traverse the string:\n                            <li>If <code>'('<\/code> \u2192 increment openCount<\/li>\n                            <li>If <code>')'<\/code>:\n                                <ul>\n                                    <li>If <code>openCount > 0<\/code> \u2192 match it <code>(openCount--)<\/code><\/li>\n                                    <li>Else \u2192 it's invalid \u2192 increment <code>moves<\/code><\/li>\n                                <\/ul>\n                            <\/li>\n                        <\/ul>\n                    <\/li>\n                    <li>At the end, Add remaining unmatched <code>'('<\/code> <code>(openCount)<\/code> to <code>moves<\/code><\/li>\n                <\/ul>\n\n<h2>Dry Run<\/h2>\n<div style=\"background: var(--light-bg); border-left: 4px solid var(--primary); padding: 1rem; border-radius: var(--tab-radius); margin: 1rem 0; color: var(--text-dark);\"> \n  <p><strong>Input:<\/strong> <code>s = \"())(\"<\/code><\/p> \n  \n  <pre style=\"white-space: pre-wrap; background: var(--code-bg); padding: 1rem; border-radius: 8px; overflow-x: auto; color: var(--code-text);\">\nInitial:\n   openCount = 0\n   moves = 0\n\nStep 1: c = '('\n   openCount++ \u2192 openCount = 1\n   moves = 0\n\nStep 2: c = ')'\n   openCount > 0 \u2192 openCount--\n   openCount = 0\n   moves = 0\n\nStep 3: c = ')'\n   openCount == 0 \u2192 moves++\n   openCount = 0\n   moves = 1\n\nStep 4: c = '('\n   openCount++ \u2192 openCount = 1\n   moves = 1\n\nEnd of loop:\n   openCount = 1 (unmatched '(')\n   moves = 1 (extra ')')\n\nResult:\n   return moves + openCount = 1 + 1 = 2\n  <\/pre> \n  \n  <p><strong>Output:<\/strong> <code>2<\/code><\/p> \n<\/div>\n<\/div>\n\n\n<div class=\"wp_blog_code-tabs-container\">\n    <div class=\"wp_blog_code-tabs-header\">\n        <button class=\"wp_blog_code-tab-button active\" data-lang=\"js\">\n            JavaScript\n        <\/button>\n        <button class=\"wp_blog_code-tab-button\" data-lang=\"py\">Python<\/button>\n        <button class=\"wp_blog_code-tab-button\" data-lang=\"java\">Java<\/button>\n        <button class=\"wp_blog_code-tab-button\" data-lang=\"cpp\">C++<\/button>\n        <button class=\"wp_blog_code-tab-button\" data-lang=\"c\">C<\/button>\n        <button class=\"wp_blog_code-tab-button\" data-lang=\"cs\">C#<\/button>\n    <\/div>\n\n    <div class=\"wp_blog_code-tab-content active\" data-lang=\"js\">\n        <pre><code class=\"language-javascript\">\nvar minAddToMakeValid = function(s) {\n    let openCount = 0, moves = 0;\n\n    for (let c of s) {\n        if (c == \"(\") {\n            openCount++;\n        } else {\n            if (openCount == 0) {\n                moves++;\n            } else {\n                openCount--; \/\/ FIXED\n            }\n        }\n    }\n\n    return moves + openCount;\n};\n    <\/code><\/pre>\n    <\/div>\n    <div class=\"wp_blog_code-tab-content\" data-lang=\"py\">\n        <pre><code class=\"language-python\">\ndef minAddToMakeValid(s: str) -> int:\n    openCount = 0\n    moves = 0\n\n    for c in s:\n        if c == '(':\n            openCount += 1\n        else:\n            if openCount == 0:\n                moves += 1\n            else:\n                openCount -= 1\n\n    return moves + openCount\n    <\/code><\/pre>\n    <\/div>\n    <div class=\"wp_blog_code-tab-content\" data-lang=\"java\">\n        <pre><code class=\"language-java\">\nclass Solution {\n    public int minAddToMakeValid(String s) {\n        int openCount = 0, moves = 0;\n\n        for (char c : s.toCharArray()) {\n            if (c == '(') {\n                openCount++;\n            } else {\n                if (openCount == 0) {\n                    moves++;\n                } else {\n                    openCount--;\n                }\n            }\n        }\n\n        return moves + openCount;\n    }\n}\n<\/code><\/pre>\n    <\/div>\n    <div class=\"wp_blog_code-tab-content\" data-lang=\"cpp\">\n        <pre><code class=\"language-cpp\">\nclass Solution {\npublic:\n    int minAddToMakeValid(string s) {\n        int openCount = 0, moves = 0;\n\n        for (char c : s) {\n            if (c == '(') {\n                openCount++;\n            } else {\n                if (openCount == 0) {\n                    moves++;\n                } else {\n                    openCount--;\n                }\n            }\n        }\n\n        return moves + openCount;\n    }\n};\n    <\/code><\/pre>\n    <\/div>\n    <div class=\"wp_blog_code-tab-content\" data-lang=\"c\">\n        <pre><code class=\"language-c\">\n#include &lt;stdio.h&gt;\n\nint minAddToMakeValid(char* s) {\n    int openCount = 0, moves = 0;\n\n    for (int i = 0; s[i] != '\\0'; i++) {\n        if (s[i] == '(') {\n            openCount++;\n        } else {\n            if (openCount == 0) {\n                moves++;\n            } else {\n                openCount--;\n            }\n        }\n    }\n\n    return moves + openCount;\n}\n   <\/code><\/pre>\n    <\/div>\n    <div class=\"wp_blog_code-tab-content\" data-lang=\"cs\">\n        <pre><code class=\"language-csharp\">\npublic class Solution {\n    public int MinAddToMakeValid(string s) {\n        int openCount = 0, moves = 0;\n\n        foreach (char c in s) {\n            if (c == '(') {\n                openCount++;\n            } else {\n                if (openCount == 0) {\n                    moves++;\n                } else {\n                    openCount--;\n                }\n            }\n        }\n\n        return moves + openCount;\n    }\n}\n  <\/code><\/pre>\n    <\/div>\n<\/div>\n<\/div>\n\n<script>\ndocument.addEventListener(\"DOMContentLoaded\", () => {\n  const buttons = document.querySelectorAll(\".wp_blog_code-tab-button\");\n  const contents = document.querySelectorAll(\".wp_blog_code-tab-content\");\n\n  buttons.forEach((button) => {\n    button.addEventListener(\"click\", () => {\n      const lang = button.getAttribute(\"data-lang\");\n\n      buttons.forEach((btn) => btn.classList.remove(\"active\"));\n      contents.forEach((content) => content.classList.remove(\"active\"));\n\n      button.classList.add(\"active\");\n      document\n        .querySelector(`.wp_blog_code-tab-content[data-lang=\"${lang}\"]`)\n        .classList.add(\"active\");\n    });\n  });\n\n  const themeToggle = document.getElementById(\"blogNotesThemeToggle\");\n  const themeContainer = document.querySelector(\".wp_blog_theme\");\n\n  themeToggle.addEventListener(\"click\", () => {\n    themeContainer.classList.toggle(\"dark-mode\");\n    themeToggle.textContent =\n      themeContainer.classList.contains(\"dark-mode\") ? \"\u2600\ufe0f\" : \"\ud83c\udf19\";\n  });\n});\n<\/script>\n\n\n","protected":false},"excerpt":{"rendered":"<p>\ud83c\udf19 Problem Statement: A parentheses string is valid if and only if: It is the empty string, It can be written as AB (A concatenated with B), where A and B are valid strings, or It can be written as (A), where A is a valid string. You are given a parentheses string s. In<\/p>\n","protected":false},"author":108,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[210,322,260,176,175,211,811,810,174,172,173],"tags":[],"class_list":["post-12199","post","type-post","status-publish","format-standard","category-algorithms","category-algorithms-and-data-structures","category-c-c-plus-plus","category-csharp","category-cplusplus","category-data-structures","category-data-structures-and-algorithms","category-dsa","category-java","category-javascript","category-python"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/posts\/12199","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/users\/108"}],"replies":[{"embeddable":true,"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/comments?post=12199"}],"version-history":[{"count":1,"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/posts\/12199\/revisions"}],"predecessor-version":[{"id":12200,"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/posts\/12199\/revisions\/12200"}],"wp:attachment":[{"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/media?parent=12199"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/categories?post=12199"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/namastedev.com\/blog\/wp-json\/wp\/v2\/tags?post=12199"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}