1 files changed, 55 insertions, 0 deletions
diff --git a/cpp/somme.cpp b/cpp/somme.cpp
new file mode 100644
index 0000000..df8f8ee
--- /dev/null
+++ b/cpp/somme.cpp
@@ -0,0 +1,55 @@
+/* gator 2017
+input: 1 5
+output: 1
+*/
+
+#include <iostream>
+#include <fstream>
+
+bool pari(int n) { return ((n % 2) == 0) ? true : false; }
+
+int sequenza(int n, bool pollatz, int tCollatz = -1)
+{
+	int m, tot = 1;
+	
+	if(pollatz)
+		m = 5;
+	else
+		m = 3;
+
+	while(n != 1) {		
+		if(pari(n))
+			n /= 2;
+		else
+			n = n*m+1;
+		
+		tot++;
+		
+		if(tCollatz != -1 && tot > tCollatz)
+			break;
+	}
+	
+	return tot;
+}
+
+int main()
+{
+	std::ifstream in("input.txt");
+	std::ofstream out("output.txt");
+	
+	int N1, N2, tot = 0, collatz;
+	in >> N1 >> N2;
+	
+	for(int i = N1; i <= N2; i++) {
+		collatz = sequenza(i, false);
+		if(sequenza(i, true, collatz) < collatz)
+			tot++;
+	}
+	
+	out << tot;
+	
+	out.close();
+	in.close();
+	
+	return 0;
+}
+\ No newline at end of file