Solved a bunch of problems

1 files changed, 107 insertions, 0 deletions

diff --git a/contests/Round#853/B/main.cpp b/contests/Round#853/B/main.cpp
new file mode 100755
index 0000000..12517e2
--- /dev/null
+++ b/contests/Round#853/B/main.cpp
@@ -0,0 +1,107 @@
+#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
+ */
+
+bool isPalindrome(string &s) { return string(all(s)) == string(rall(s)); }
+
+void solve() {
+  int n;
+  cin >> n;
+  string s;
+  cin >> s;
+  vector<bool> pal(n);
+  if (n & 1)
+    pal[n / 2] = 1;
+  for (int i = 0; i < n / 2; i++) {
+    pal[i] = pal[n - i - 1] = s[i] == s[n - i - 1];
+  }
+  pal.erase(unique(all(pal)), pal.end());
+  n = pal.size();
+  if (count(all(pal), 0) <= 2) {
+    cout << "Yes" << '\n';
+  } else {
+    cout << "No" << '\n';
+  }
+  // string haystack = "";
+  // for (int i = 0; i < n / 2; i++) {
+  //   haystack += (pal[i] ? "R" : "W");
+  // }
+  // if (regex_match(haystack, regex("WR+W"))) {
+  //   cout << "No" << '\n';
+  // } else {
+  //   cout << "Yes" << '\n';
+  // }
+}
+
+int main() {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  int tt;
+  cin >> tt;
+  while (tt--) {
+    solve();
+  }
+}