Solved a dp problem on codeforces

1 files changed, 107 insertions, 0 deletions

diff --git a/codeforces/SerejaAndSuffixes/main.cpp b/codeforces/SerejaAndSuffixes/main.cpp
new file mode 100755
index 0000000..c14fd91
--- /dev/null
+++ b/codeforces/SerejaAndSuffixes/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
+ */
+
+void solve() {
+  int n, m;
+  cin >> n >> m;
+  vi v(n);
+  vi q(m);
+  set<int> st;
+  for (auto &x : v) {
+    cin >> x;
+    st.insert(x);
+  } 
+  for (auto &x : q) cin >> x;
+  vi fq(1e5 + 5);
+  vi dp(n);
+  dp[0] = st.size();
+  for (int i = 0; i < n; i++) {
+    fq[v[i]]++;
+  }
+  for (int i = 1; i < n; i++) {
+    fq[v[i - 1]]--;
+    dp[i] = dp[i - 1] - (fq[v[i - 1]] == 0);
+  }
+  for (auto x : q) {
+    cout << dp[x - 1] << '\n';
+  }
+}
+
+int main () {
+  ios_base::sync_with_stdio(false);
+  cin.tie(NULL);
+  solve();
+}
+
+