Added problem 584D from codeforces

Author: jhonber

codeforces/Codeforces Round #324 (Div. 2)/D.cpp

@@ -0,0 +1,102 @@
+// http://codeforces.com/contest/584/problem/D
+
+#include<bits/stdc++.h>
+using namespace std;
+#define __ ios_base::sync_with_stdio(0); cin.tie(0);
+#define endl '\n'
+#define foreach(it, x) for (__typeof (x).begin() it = (x).begin(); it != (x).end(); ++it)
+#define all(x) x.begin(),x.end()
+#define D(x) cout << #x " = " << (x) << endl;
+
+template <class T> string toStr(const T &x)
+{ stringstream s; s << x; return s.str(); }
+
+template <class T> int toInt(const T &x)
+{ stringstream s; s << x; int r; s >> r; return r; }
+
+int dx[8] = {-1,-1,-1,0,1,1, 1, 0};
+int dy[8] = {-1, 0, 1,1,1,0,-1,-1};
+
+vector<int> primes;
+
+void gen_primes (int lim) {
+  primes.push_back(2);
+
+  for (int p = 3; p <= lim; p += 2) {
+    int i = 2;
+    int f = true;
+    while (i * i <= p) {
+      if (p % i == 0) {
+        f = false;
+        break;
+      }
+      i ++;
+    }
+
+    if (f) primes.push_back(p);
+  }
+}
+
+bool is_prime(int n) {
+  if (n < 2) return false;
+  if (n == 2) return true;
+  int i = 2;
+  while (i * i <= n) {
+    if (n % i == 0) return false;
+    i ++;
+  }
+  return true;
+}
+
+int main() {
+  int mx = 1e6;
+  gen_primes(mx);
+
+  int n;
+  cin >> n;
+
+  int n2 = n;
+  int tmp = n;
+
+  while (n2 > 0) {
+    if (!is_prime(n2)) {
+      n2 --;
+      continue;
+    }
+
+    n = tmp;
+    int f = false;
+    vector<int> ans;
+    ans.push_back(n2);
+    n -= n2;
+
+    if (!n) f = true;
+
+    for (int i = 0; n > 0 && i < primes.size(); ++i) {
+      if (primes[i] <= n) {
+        int rest = n - primes[i];
+        if (rest == 0) {
+          ans.push_back(primes[i]);
+          f = true;
+          break;
+        }
+        if (is_prime(rest)) {
+          ans.push_back(primes[i]);
+          ans.push_back(rest);
+          f = true;
+          break;
+        }
+      }
+      else break;
+    }
+
+    if (f) {
+      cout << ans.size() << endl;
+      for (int i = 0; i < ans.size(); ++i) cout << ans[i] << " ";
+      return 0;
+    }
+    n2 --;
+  }
+
+  return 0;
+}

codeforces/data.db

@@ -676,4 +676,5 @@
 13421744
 13425589
 13463792
-13443199
+13443199
+13465613