From 680936f50a2008cacaa899f527da4de000901d8b Mon Sep 17 00:00:00 2001
From: Richard Thier <magosit@outlook.hu>
Date: Tue, 16 Aug 2022 04:13:12 +0200
Subject: [PATCH] still buggy sp code but differently...

---
 space_partitioning_sort/spsort.h | 11 ++++++-----
 ypsu.cpp                         |  6 +++---
 2 files changed, 9 insertions(+), 8 deletions(-)

diff --git a/space_partitioning_sort/spsort.h b/space_partitioning_sort/spsort.h
index 91d428e..ae29733 100644
--- a/space_partitioning_sort/spsort.h
+++ b/space_partitioning_sort/spsort.h
@@ -101,22 +101,23 @@ inline void internal_spsort(uint32_t *t, int n, int m, uint32_t low, uint32_t mi
 	// Init left-right "write head" indices
 	int left = 0;
 	int right = n - 1;
-
 	uint32_t current = t[left];
+	bool current_is_left = true;
 
 	// Separate to the ends of the array (in-place)
-	// We avoid the first location to hold invariant!
-	for(int i = 1; i < n; ++i) {
-		// TODO: maybe std::swaps below can be faster when generalizing?
+	for(int i = 0; i < n; ++i) {
 		if(current < mid) {
 			const auto tmp = t[left];
 			t[left++] = current;
-			current = tmp;
+			current = current_is_left ? t[left] : tmp;
+			current_is_left = true;
 
 		} else {
 			const auto tmp = t[right];
 			t[right--] = current;
 			current = tmp;
+			current = !current_is_left ? t[right] : tmp;
+			current_is_left = false;
 		}
 	}
 
diff --git a/ypsu.cpp b/ypsu.cpp
index 1b39d96..c0fb400 100644
--- a/ypsu.cpp
+++ b/ypsu.cpp
@@ -32,8 +32,8 @@
     worst[name] = std::max(worst[name], seconds);
   }
   std::vector<std::string> inputtypes = {
-      "constant", "asc",      "desc",       "ascasc", "ascdesc",
-      "descasc",  "descdesc", "smallrange", "rand",
+      /*"constant", "asc",      "desc",       "ascasc", "ascdesc",
+      "descasc",  "descdesc", "smallrange",*/ "rand",
   };
   std::vector<uint32_t> geninput(const std::string &type, int n) {
     std::vector<uint32_t> v(n);
@@ -395,7 +395,7 @@
   int main(void) {
     //int n = 100000000;
     //int n = 10000000;
-    int n = 100;
+    int n = 64;
     for (auto inputtype : inputtypes) {
       printf("%10s", inputtype.c_str());
       fflush(stdout);