project-euler

commit e3aa186b08e7ccdf1f4b6b89aa1724864df0bff7
parent 4cf43d5967c68f9b6ac3e1ae3163802f1a7e9426
Author: mpizzzle <m@michaelpercival.xyz>
Date:   Sun, 27 Sep 2020 22:40:26 +0100

refactoring both loops into one

Diffstat:
M
Euler_95.cpp
 | 
34
++++++++++++++--------------------

1 file changed, 14 insertions(+), 20 deletions(-)
diff --git a/Euler_95.cpp b/Euler_95.cpp
@@ -11,45 +11,39 @@ int Euler::AmicableChains()
     for (int i = 2; i < root; ++i) {
         for (int j = 2; i * j <= one_million; ++j) {
             divisors[i * j] += i + ((j >= root) ? j : 0);
-	}
+        }
     }
 
     for (int n = 1; n <= one_million; ++n) {
         int length = 0;
         int candidate = one_million;
         int slow_ptr = n, fast_ptr = n;
+        bool loop_found = false;
 
         while(fast_ptr > 1 && slow_ptr <= one_million && fast_ptr <= one_million) {
+            length += loop_found;
             fast_ptr = divisors[fast_ptr];
 
             if (fast_ptr <= 1 || fast_ptr > one_million) {
                 break;
             }
 
-            if (slow_ptr == fast_ptr) {
-                while (true) {
-                    length++;
-                    fast_ptr = divisors[fast_ptr];
-
-                    if (slow_ptr < candidate) {
-                        candidate = slow_ptr;
-                    }
-
-                    if (slow_ptr == fast_ptr) {
-                        if (length > longest) {
-                            solution = candidate;
-                            longest = length;
-                        }
+            if (loop_found && slow_ptr < candidate) {
+                candidate = slow_ptr;
+            }
 
-			divisors[candidate] = 1;
-                        break;
+            if (slow_ptr == fast_ptr) {
+                if (loop_found) {
+                    if (length > longest) {
+                        solution = candidate;
+                        longest = length;
                     }
 
-                    slow_ptr = divisors[slow_ptr];
-                    fast_ptr = divisors[fast_ptr];
+                    divisors[candidate] = 1;
+                    break;
                 }
 
-                break;
+                loop_found = true;
             }
 
             slow_ptr = divisors[slow_ptr];