From 00e23909f8599686ae8aa975a7f5a443a500516f Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Stefan=20B=C3=BChler?= <stbuehler@web.de>
Date: Sat, 7 Oct 2017 23:21:45 +0200
Subject: [PATCH] fix loop condition

prev[sink] == 0 means there was a path found with the last step being a
forward edge to the sink, and the edge being at index 0 in the array.

This is a valid path (the same as any other path indicated by prev[sink]
> 0).
---
 maxflow.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/maxflow.c b/maxflow.c
index 028946b..97ae8c4 100644
--- a/maxflow.c
+++ b/maxflow.c
@@ -80,7 +80,7 @@ int maxflow_with_scratch(void *scratch, int nv, int source, int sink,
 	/*
 	 * Now do the BFS loop.
 	 */
-	while (head < tail && prev[sink] <= 0) {
+	while (head < tail && prev[sink] < 0) {
 	    from = todo[head++];
 
 	    /*