Day 4

2019/4thDay/challenge2.cpp

@@ -0,0 +1,44 @@
+#include <algorithm>
+#include <iostream>
+#include <string>
+
+bool checkPassword( std::string pass )
+{
+
+    // Is less than 6
+    if ( pass.length() > 6 || pass.length() < 6 ) return false;
+
+    // Digets never decrease
+    bool decreases = true;
+    for ( int i = 1; i < pass.length(); i++ )
+        if ( pass[i - 1] > pass[i] ) decreases = false;
+
+    if ( !decreases ) return false;
+
+    // No repeats ( conform w part 2 rule )
+    if ( std::any_of( pass.begin(), pass.end(), 
+    [&]( auto d ) {
+        return std::count( pass.begin(), pass.end(), d ) == 2; 
+    } ) )
+    {
+        return true;
+    }
+
+    return false;
+
+}
+
+int main(int argc, char** argv)
+{
+
+    int upper = 893698;
+    int lower = 367479;
+
+    int accumilator = 0;
+    for ( int i = lower; i < upper; i++ )
+        if ( checkPassword( std::to_string( i ) ) )
+            accumilator++;
+
+    std::cout << "There are : " << accumilator << " valid passwords" << std::endl;
+
+}