[Init] Solved solutions

cpp/110A.cpp

@@ -0,0 +1,27 @@
+#include <iostream>
+#include <string>
+
+using namespace std;
+
+int main()
+{
+    string s;
+    cin >> s;
+    int sum = 0;
+    for (string::iterator i = s.begin(); i != s.end(); i++)
+    {
+        if (*i == '4' || *i == '7')
+        {
+            sum++;
+        }
+    }
+    if (sum == 4 || sum == 7)
+    {
+        cout << "YES";
+    }
+    else
+    {
+        cout << "NO";
+    }
+    return 0;
+}