From 664405be5f22ce10a92c63e7bc994becbe8d460a Mon Sep 17 00:00:00 2001
From: jombas <jaummoura15@gmail.com>
Date: Tue, 22 Oct 2019 19:50:57 -0300
Subject: [PATCH] Added CollatzNumber algorithm

---
 CollatzNumber.c | 68 +++++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 68 insertions(+)
 create mode 100644 CollatzNumber.c

diff --git a/CollatzNumber.c b/CollatzNumber.c
new file mode 100644
index 0000000..239b58c
--- /dev/null
+++ b/CollatzNumber.c
@@ -0,0 +1,68 @@
+/*
+How this sequence works ??
+Basically, it pick a number and than check if this number is
+even or odd. 
+If the number is even then we divide it by 2,
+if it's odd just multiply by 3 and add 1 more.
+After a while the sequence becomes continuous in 1,
+this is why ...
+And of course only numbers > 0 will work.
+
+Some INPUT/OUTPUT example:
+-Imput: Contain the number to make the Collatz Sequence of it
+
+-Output: Contain a single line output that contains all the Collatz sequence
+
+TESTCASE:
+Enter a number to calcule collatz: 34
+The collatz sequence is: 34 17 52 26 13 40 20 10 5 16 8 4 2 1...
+*/
+
+#include <stdio.h>
+
+int v[1000000];
+int i = 0;
+
+int makeCollatz(int n){
+    if(n <= 0){
+        return 0;
+    }
+    else if(n == 1){
+        return 1;
+    }
+    else{
+        v[i] = n;
+        i++;
+        if(n % 2 == 0){
+            n /= 2;
+        }
+        else{
+            n = 3 * n + 1;
+        }
+    }
+    return makeCollatz(n);
+}
+
+int main(void){
+    int number, aux;
+
+    printf("Enter a number to calcule collatz: \n");
+    scanf("%d", &number);
+    aux = makeCollatz(number);
+    if(aux == 0){
+        printf("Error\n");
+    }
+    else if(aux == 1){
+        v[i] = 1;
+        i++;
+    }
+
+    printf("The collatz sequence is: \n");
+    printf("%d", v[0]);
+    for(int j = 1; j < i; j++){
+        printf(" %d", v[j]);
+    }
+    printf("...\n");
+
+    return 0;
+}