Solved a bunch of problems

121 files changed, 3538 insertions, 23 deletions

diff --git a/codechef/ConcatPalindrome/main b/codechef/ConcatPalindrome/main
new file mode 100755
index 0000000..949fc76
--- /dev/null
+++ b/codechef/ConcatPalindrome/main
diff --git a/codechef/ConcatPalindrome/main.cpp b/codechef/ConcatPalindrome/main.cpp
new file mode 100755
index 0000000..37c41d5
--- /dev/null
+++ b/codechef/ConcatPalindrome/main.cpp
@@ -0,0 +1,130 @@
+#include<bits/stdc++.h>
+using namespace std;
+
+using ll = long long;
+using pi = pair<int, int>;
+using vpi = vector<pi>;
+using vi = vector<int>;
+using vll = vector<long long>;
+using mpii = map<int, int>;
+using mpll = map<ll, ll>;
+using db = long double;
+
+#define pb push_back 
+#define all(x) (x).begin(), (x).end()
+#define rall(x) (x).rbegin(), (x).rend()
+#define lb lower_bound
+#define ub upper_bound
+
+const int MOD = (int)1e9 + 7;
+const db PI = acos((db)-1);
+const int dx[4]{1, 0, -1, 0};
+const int dy[4]{0, 1, 0, -1};
+
+//pretty printing
+template<typename K, typename V>
+void printm(const map<K, V> &mp) {
+  cerr << "{" << endl;
+  for (auto p : mp) {
+    cerr << "  { " << p.first << " : " << p.second << " }\n";
+  }
+  cerr << "}" << endl;
+}
+template<typename T>
+void printv(const vector<T> &v) {
+  cerr << "[";
+  for (int i = 0; i < v.size(); i++) {
+    if (i == v.size() - 1) {
+      cerr << v[i];
+    } else {
+      cerr << v[i] << ", ";
+    }
+  }
+  cerr << "]\n";
+}
+
+template<typename T>
+void printvv(const vector<vector<T>> &v) {
+  cerr << "[\n";
+  for (auto &vec : v) {
+    cout << "  ";
+    printv(vec);
+  }
+  cerr << "]\n";
+}
+void print() {
+  cerr << "\n";
+}
+
+template<typename T, typename... TS>
+void print(T val, TS... vals) {
+  cerr << val << " ";
+  print(vals...);
+}
+
+
+/* stuff you should look for:
+  ---------------------------
+   * special cases (n=1?)
+   * int overflow, array bounds
+   * do smth instead of nothing and stay organized
+   * WRITE STUFF DOWN
+   * DON'T GET STUCK ON ONE APPROACH
+ */
+
+// dddaddd
+// abcba
+// dcaaacd
+
+void solve() {
+  int n, m;
+  cin >> n >> m;
+  string a, b;
+  cin >> a >> b;
+  set<char> st;
+  string ab = a + b;
+  vector<int> fq('z' - 'a' + 2);
+  for(auto ch : ab) {
+    st.insert(ch);
+    fq[ch - 'a']++;
+  }
+  int even = 0;
+  int odd = 0;
+  if ((n + m) % 2 == 0) {
+    for (auto ch : st) {
+      even += fq[ch - 'a'] % 2 == 0;
+    }
+    cout << (even == st.size() ? "YES" : "NO") << '\n';
+  } else {
+    char cho;
+    for (auto ch : st) {
+      even += fq[ch - 'a'] % 2 == 0;
+      if (fq[ch - 'a'] % 2 != 0) {
+        odd += fq[ch - 'a'] % 2 != 0;
+        cho = ch;
+      }
+    }
+    if (odd == 1) {
+      if (n > m) {
+        cout << (count(all(a), cho) ? "YES" : "NO") << '\n';
+      } else {
+        cout << (count(all(b), cho) ? "YES" : "NO") << '\n';
+      }
+    } else {
+      cout << "NO" << '\n';
+    }
+  }
+
+}
+
+int main () {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  int tt;
+  cin >> tt;
+  while(tt--) {
+    solve();
+  }
+}
+
+
diff --git a/codechef/ConcatPalindrome/main_input0.txt b/codechef/ConcatPalindrome/main_input0.txt
new file mode 100644
index 0000000..a2f3667
--- /dev/null
+++ b/codechef/ConcatPalindrome/main_input0.txt
@@ -0,0 +1,13 @@
+4
+5 2
+abcdd
+ac
+3 3
+abc
+xyz
+2 4
+aa
+aaaa
+1 3
+a
+aax
diff --git a/codechef/ConcatPalindrome/main_input1.txt b/codechef/ConcatPalindrome/main_input1.txt
new file mode 100644
index 0000000..39c23ff
--- /dev/null
+++ b/codechef/ConcatPalindrome/main_input1.txt
@@ -0,0 +1,4 @@
+1
+3 4
+aaa
+cddc
\ No newline at end of file
diff --git a/codechef/ConcatPalindrome/main_input2.txt b/codechef/ConcatPalindrome/main_input2.txt
new file mode 100644
index 0000000..e59d54e
--- /dev/null
+++ b/codechef/ConcatPalindrome/main_input2.txt
@@ -0,0 +1,4 @@
+1
+5 2
+accdd
+ax
\ No newline at end of file
diff --git a/codechef/ConcatPalindrome/main_output0.txt b/codechef/ConcatPalindrome/main_output0.txt
new file mode 100644
index 0000000..2bc7799
--- /dev/null
+++ b/