From dee6d2782db5c9d5bbab1bbb8d2bd9ff9f6fd34a Mon Sep 17 00:00:00 2001
From: Mohammad S Anwar <mohammad.anwar@yahoo.com>
Date: Wed, 27 Dec 2023 11:07:16 +0000
Subject: - Added solutions by Ulrich Rieke. - Added solutions by Dave Jacoby.
 - Added solutions by Stephen G Lynn.

---
 challenge-249/ulrich-rieke/cpp/ch-2.cpp | 63 +++++++++++++++++++++++++++++++++
 1 file changed, 63 insertions(+)
 create mode 100755 challenge-249/ulrich-rieke/cpp/ch-2.cpp

(limited to 'challenge-249/ulrich-rieke/cpp/ch-2.cpp')

diff --git a/challenge-249/ulrich-rieke/cpp/ch-2.cpp b/challenge-249/ulrich-rieke/cpp/ch-2.cpp
new file mode 100755
index 0000000000..8f52f5dcfb
--- /dev/null
+++ b/challenge-249/ulrich-rieke/cpp/ch-2.cpp
@@ -0,0 +1,63 @@
+#include <string>
+#include <iostream>
+#include <algorithm>
+#include <vector>
+#include <numeric>
+
+bool isValid( const std::vector<int> & permu , const std::vector<int> & the_is , 
+      const std::vector<int> & the_ds ) {
+   for ( int i = 0 ; i < the_is.size( ) ; i++ ) {
+      int pos = the_is[ i ] ;
+      if ( permu[pos] >= permu[ pos + 1] ) { 
+	 return false ;
+      }
+   }
+   for ( int i = 0 ; i < the_ds.size( ) ; i++ ) { 
+      int pos = the_ds[ i ] ;
+      if ( permu[pos] <= permu[ pos + 1 ] ) {
+	 return false ;
+      }
+   }
+   return true ;
+}
+
+int main( ) {
+   std::cout << "Please enter a string consisting of capital I and D only!\n" ;
+   std::string line ;
+   std::cin >> line ;
+   std::vector<int> ipositions ;
+   std::vector<int> dpositions ;
+   for ( int i = 0 ; i < line.length( ) ; i++ ) {
+      if ( line.substr( i , 1 ) == "I" ) 
+	 ipositions.push_back( i ) ;
+      else
+	 dpositions.push_back( i ) ;
+   }
+   int len = line.length( ) ;
+   std::vector<int> numbers ( len + 1 ) ;
+   std::iota( numbers.begin( ) , numbers.end( ) , 0 ) ;
+   std::vector<int> result ;
+   if ( dpositions.empty( ) ) {
+      result = numbers ;
+   }
+   else {
+      if ( ipositions.empty( ) ) {
+	 result = numbers ;
+	 std::reverse( result.begin( ) , result.end( ) ) ;
+      }
+      else {
+	 while ( std::next_permutation( numbers.begin( ) , numbers.end( ) ) ) {
+	    if ( isValid( numbers, ipositions, dpositions ) ) { 
+	       result = numbers ;
+	       break ;
+	    }
+         }
+      }
+   }
+   std::cout << "( " ;
+   for ( int i : result ) {
+      std::cout << i << " " ;
+   }
+   std::cout << " )\n" ;
+   return 0 ;
+}
-- 
cgit