From 64a1365c054977ebe530885b3bc5996a14211de3 Mon Sep 17 00:00:00 2001
From: Kim Walisch <kim.walisch@gmail.com>
Date: Mon, 8 Jan 2024 12:21:20 +0100
Subject: [PATCH] Fix bounds

---
 src/nthPrime.cpp | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/src/nthPrime.cpp b/src/nthPrime.cpp
index 1d9548974..fb18268af 100644
--- a/src/nthPrime.cpp
+++ b/src/nthPrime.cpp
@@ -150,7 +150,7 @@ uint64_t PrimeSieve::negativeNthPrime(int64_t n, uint64_t start)
   // we simply iterate over the primes until we find it.
   if (countApprox >= n)
   {
-    uint64_t dist = (n - countApprox) * avgPrimeGap(start);
+    uint64_t dist = (countApprox - n) * avgPrimeGap(start);
     uint64_t stop = checkedAdd(start, dist);
     primesieve::iterator iter(start, stop);
     for (int64_t i = countApprox; i >= n; i--)
@@ -159,7 +159,7 @@ uint64_t PrimeSieve::negativeNthPrime(int64_t n, uint64_t start)
   else // if (countApprox < n)
   {
     start = checkedSub(start, 1);
-    uint64_t dist = (countApprox - n) * avgPrimeGap(start);
+    uint64_t dist = (n - countApprox) * avgPrimeGap(start);
     uint64_t stop = checkedSub(start, dist);
     primesieve::iterator iter(start, stop);
     for (int64_t i = countApprox; i < n; i++)