From 70c8441a837563a8ca3b506f768b94b5d3bec7db Mon Sep 17 00:00:00 2001
From: ShazidMahsrafi <shazid456@gmail.com>
Date: Thu, 1 Aug 2024 04:42:14 +0600
Subject: [PATCH] feat: Add solutions for Codeforces problems 1997 A, B, C, and
 D

---
 Codes/1997 A - Strong Password/1997A.cpp    | 53 +++++++++++++++
 Codes/1997 B - Make Three Regions/1997B.cpp | 65 +++++++++++++++++++
 Codes/1997 C - Even Positions/1997C.cpp     | 72 +++++++++++++++++++++
 Codes/1997 D - Maximize the Root/1997D.cpp  | 61 +++++++++++++++++
 Readme.md                                   |  4 ++
 5 files changed, 255 insertions(+)
 create mode 100644 Codes/1997 A - Strong Password/1997A.cpp
 create mode 100644 Codes/1997 B - Make Three Regions/1997B.cpp
 create mode 100644 Codes/1997 C - Even Positions/1997C.cpp
 create mode 100644 Codes/1997 D - Maximize the Root/1997D.cpp

diff --git a/Codes/1997 A - Strong Password/1997A.cpp b/Codes/1997 A - Strong Password/1997A.cpp
new file mode 100644
index 0000000..22bcba2
--- /dev/null
+++ b/Codes/1997 A - Strong Password/1997A.cpp	
@@ -0,0 +1,53 @@
+#include <bits/stdc++.h>
+using namespace std;
+#ifdef ONLINE_JUDGE
+#define dbg(...)
+#else
+#include "Assets/debug.h"
+#endif
+#define  int  long long
+#define  ll  long long
+#define  endl  '\n'
+#define  ff  first
+#define  ss  second
+#define  ins  insert
+#define  pb  push_back
+#define  ppb  pop_back
+#define  sz(x)  (int)(x).size()
+#define  all(x)  x.begin(), x.end()
+#define  rep(i,a,b)  for(int i=a; i<b; ++i)
+#define  rrep(i,a,b) for(int i=a; i>=b; --i)
+#define  yn(f)  f? cout<<"YES\n":cout<<"NO\n"
+#define  FAST  (ios_base::sync_with_stdio(false), cin.tie(nullptr));
+ll pow(ll x,ll y,ll m=1e9+7) {ll ans=1;x%=m;while(y){if(y&1)ans=(ans*x)%m;x=(x*x)%m;y>>=1;}return ans;}
+
+void solve()
+{
+    string s;
+    cin>>s;
+    for(int i=1; i<s.size(); ++i)
+    {
+        if(s[i]==s[i-1])
+        {
+            if(s[i]=='a')   s.insert(s.begin()+i,'b');
+            else    s.insert(s.begin()+i,'a');
+            cout<<s<<endl;
+            return;
+        }
+    }
+    if(s.back()=='a')   s.append("b");
+    else    s.append("a");
+    cout<<s<<endl;
+}
+
+signed main()
+{
+    FAST;
+    int TCS = 1;
+    cin >> TCS;
+    for (int TC = 1; TC <= TCS; ++TC)
+    {
+      // cout<<"Case "<<TC<<": ";
+      solve();
+    }
+}
\ No newline at end of file
diff --git a/Codes/1997 B - Make Three Regions/1997B.cpp b/Codes/1997 B - Make Three Regions/1997B.cpp
new file mode 100644
index 0000000..9eb5711
--- /dev/null
+++ b/Codes/1997 B - Make Three Regions/1997B.cpp	
@@ -0,0 +1,65 @@
+#include <bits/stdc++.h>
+using namespace std;
+#ifdef ONLINE_JUDGE
+#define dbg(...)
+#else
+#include "Assets/debug.h"
+#endif
+#define  int  long long
+#define  ll  long long
+#define  endl  '\n'
+#define  ff  first
+#define  ss  second
+#define  ins  insert
+#define  pb  push_back
+#define  ppb  pop_back
+#define  sz(x)  (int)(x).size()
+#define  all(x)  x.begin(), x.end()
+#define  rep(i,a,b)  for(int i=a; i<b; ++i)
+#define  rrep(i,a,b) for(int i=a; i>=b; --i)
+#define  yn(f)  f? cout<<"YES\n":cout<<"NO\n"
+#define  FAST  (ios_base::sync_with_stdio(false), cin.tie(nullptr));
+ll pow(ll x,ll y,ll m=1e9+7) {ll ans=1;x%=m;while(y){if(y&1)ans=(ans*x)%m;x=(x*x)%m;y>>=1;}return ans;}
+
+void solve()
+{
+    int n;
+    cin>>n;
+    vector<string>v(2);
+    for(auto &i:v)  cin>>i;
+    dbg(n,v);
+    int ans=0;
+    rep(i,0,2)
+    {
+        rep(j,0,n)
+        {
+            int ct=0;
+            if(j+1<n && v[i][j+1]=='.') ct++;
+            if(j-1>=0 && v[i][j-1]=='.') ct++;
+            dbg(ct);
+            if(ct<2)    continue;
+            if(i==0)
+            {   
+                if(v[i+1][j]=='.' && v[i+1][j-1]=='x' && v[i+1][j+1]=='x')  ans++;
+            }
+            else
+            {
+                if(v[i-1][j]=='.' && v[i-1][j-1]=='x' && v[i-1][j+1]=='x')  ans++;
+            }
+        }
+    }
+    cout<<ans<<endl;
+    dbg(ans);
+}
+
+signed main()
+{
+    FAST;
+    int TCS = 1;
+    cin >> TCS;
+    for (int TC = 1; TC <= TCS; ++TC)
+    {
+      // cout<<"Case "<<TC<<": ";
+      solve();
+    }
+}
\ No newline at end of file
diff --git a/Codes/1997 C - Even Positions/1997C.cpp b/Codes/1997 C - Even Positions/1997C.cpp
new file mode 100644
index 0000000..99a71f6
--- /dev/null
+++ b/Codes/1997 C - Even Positions/1997C.cpp	
@@ -0,0 +1,72 @@
+#include <bits/stdc++.h>
+using namespace std;
+#ifdef ONLINE_JUDGE
+#define dbg(...)
+#else
+#include "Assets/debug.h"
+#endif
+#define  int  long long
+#define  ll  long long
+#define  endl  '\n'
+#define  ff  first
+#define  ss  second
+#define  ins  insert
+#define  pb  push_back
+#define  ppb  pop_back
+#define  sz(x)  (int)(x).size()
+#define  all(x)  x.begin(), x.end()
+#define  rep(i,a,b)  for(int i=a; i<b; ++i)
+#define  rrep(i,a,b) for(int i=a; i>=b; --i)
+#define  yn(f)  f? cout<<"YES\n":cout<<"NO\n"
+#define  FAST  (ios_base::sync_with_stdio(false), cin.tie(nullptr));
+ll pow(ll x,ll y,ll m=1e9+7) {ll ans=1;x%=m;while(y){if(y&1)ans=(ans*x)%m;x=(x*x)%m;y>>=1;}return ans;}
+
+void solve()
+{
+    int n;
+    string s;
+    cin>>n>>s;
+    int ct=0,cost=0;
+    vector<int>v;
+    for(int i=0; i<n; ++i)
+    {
+        if(s[i]=='(')
+        {
+            ct++;
+            v.push_back(i);
+        }
+        else if(s[i]==')')
+        {
+            ct--;
+            cost += i-v.back();
+            v.pop_back();
+        }
+        else
+        {
+            if(ct)
+            {
+                ct--;
+                cost += i-v.back();
+                v.pop_back();
+            }
+            else
+            {
+                ct++;
+                v.push_back(i);
+            }
+        }
+    }
+    cout<<cost<<endl;
+}
+
+signed main()
+{
+    FAST;
+    int TCS = 1;
+    cin >> TCS;
+    for (int TC = 1; TC <= TCS; ++TC)
+    {
+      // cout<<"Case "<<TC<<": ";
+      solve();
+    }
+}
\ No newline at end of file
diff --git a/Codes/1997 D - Maximize the Root/1997D.cpp b/Codes/1997 D - Maximize the Root/1997D.cpp
new file mode 100644
index 0000000..78e6012
--- /dev/null
+++ b/Codes/1997 D - Maximize the Root/1997D.cpp	
@@ -0,0 +1,61 @@
+#include <bits/stdc++.h>
+using namespace std;
+#ifdef ONLINE_JUDGE
+#define dbg(...)
+#else
+#include "Assets/debug.h"
+#endif
+#define  int  long long
+#define  ll  long long
+#define  endl  '\n'
+#define  ff  first
+#define  ss  second
+#define  ins  insert
+#define  pb  push_back
+#define  ppb  pop_back
+#define  sz(x)  (int)(x).size()
+#define  all(x)  x.begin(), x.end()
+#define  rep(i,a,b)  for(int i=a; i<b; ++i)
+#define  rrep(i,a,b) for(int i=a; i>=b; --i)
+#define  yn(f)  f? cout<<"YES\n":cout<<"NO\n"
+#define  FAST  (ios_base::sync_with_stdio(false), cin.tie(nullptr));
+ll pow(ll x,ll y,ll m=1e9+7) {ll ans=1;x%=m;while(y){if(y&1)ans=(ans*x)%m;x=(x*x)%m;y>>=1;}return ans;}
+
+void solve()
+{
+    int n;
+    cin>>n;
+    vector<int>adj[n], v(n);
+    for(auto &i:v)  cin>>i;
+    rep(i,1,n)
+    {
+        int p;
+        cin>>p;
+        p--;
+        adj[p].pb(i);
+    }
+    function<int (int node)> dfs = [&](int node)->int 
+    {
+        int mn = INT_MAX;
+        for(auto child:adj[node]) 
+            mn = min(mn, dfs(child));
+        dbg(mn);
+        if(node == 0) return mn+v[0];
+        if(mn == INT_MAX)   return v[node];
+        if(v[node] >= mn)   return mn;
+        return (mn+v[node])/2;
+    };
+    cout<<dfs(0)<<endl;
+}
+
+signed main()
+{
+    FAST;
+    int TCS = 1;
+    cin >> TCS;
+    for (int TC = 1; TC <= TCS; ++TC)
+    {
+      // cout<<"Case "<<TC<<": ";
+      solve();
+    }
+}
\ No newline at end of file
diff --git a/Readme.md b/Readme.md
index 4aa636a..8993c59 100644
--- a/Readme.md
+++ b/Readme.md
@@ -377,6 +377,10 @@ This repository contains my solutions of Codeforces problems. They are in C++ la
 | 365 | 1996 B | Scale | [Question](https://codeforces.com/problemset/problem/1996/B) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1996%20B%20-%20Scale)
 | 366 | 1996 C | Sort | [Question](https://codeforces.com/problemset/problem/1996/C) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1996%20C%20-%20Sort)
 | 367 | 1996 D | Fun | [Question](https://codeforces.com/problemset/problem/1996/D) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1996%20D%20-%20Fun)
+| 368 | 1997 A | Strong Password | [Question](https://codeforces.com/problemset/problem/1997/A) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1997%20A%20-%20Strong%20Password)
+| 369 | 1997 B | Make Three Regions | [Question](https://codeforces.com/problemset/problem/1997/B) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1997%20B%20-%20Make%20Three%20Regions)
+| 370 | 1997 C | Even Positions | [Question](https://codeforces.com/problemset/problem/1997/C) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1997%20C%20-%20Even%20Positions)
+| 371 | 1997 D | Maximize the Root | [Question](https://codeforces.com/problemset/problem/1997/D) | [Solution](https://github.com/ShazidMashrafi/Codeforces-Solutions/tree/master/Codes/1997%20D%20-%20Maximize%20the%20Root)