From 846cb06c90fa27a52dff22655fc98a71ba60b970 Mon Sep 17 00:00:00 2001
From: Daniele Fucini <dfucini@gmail.com>
Date: Sun, 22 Sep 2019 18:26:36 +0200
Subject: [PATCH] Improve error handling

Added error handling in case of memory allocation error for
problems 35, 46, 47, 49 and 50.
---
 C/p035.c | 6 +++++-
 C/p046.c | 6 +++++-
 C/p047.c | 6 +++++-
 C/p049.c | 6 +++++-
 C/p050.c | 6 +++++-
 5 files changed, 25 insertions(+), 5 deletions(-)

diff --git a/C/p035.c b/C/p035.c
index 0399886..8b0447c 100644
--- a/C/p035.c
+++ b/C/p035.c
@@ -18,7 +18,11 @@ int main(int argc, char **argv)
 
    clock_gettime(CLOCK_MONOTONIC, &start);
 
-   primes = sieve(N);
+   if((primes = sieve(N)) == NULL)
+   {
+      fprintf(stderr, "Error! Sieve function returned NULL\n");
+      return 1;
+   }
 
    for(i = 101; i < 1000000; i += 2)
    {
diff --git a/C/p046.c b/C/p046.c
index e51ac2e..50f8de5 100644
--- a/C/p046.c
+++ b/C/p046.c
@@ -18,7 +18,11 @@ int main(int argc, char **argv)
 
    clock_gettime(CLOCK_MONOTONIC, &start);
 
-   primes = sieve(N);
+   if((primes = sieve(N)) == NULL)
+   {
+      fprintf(stderr, "Error! Sieve function returned NULL\n");
+      return 1;
+   }
 
    for(i = 3; !found && i < N; i += 2)
    {
diff --git a/C/p047.c b/C/p047.c
index 372e3e5..38a80ff 100644
--- a/C/p047.c
+++ b/C/p047.c
@@ -18,7 +18,11 @@ int main(int argc, char **argv)
 
    clock_gettime(CLOCK_MONOTONIC, &start);
 
-   primes = sieve(N);
+   if((primes = sieve(N)) == NULL)
+   {
+      fprintf(stderr, "Error! Sieve function returned NULL\n");
+      return 1;
+   }
 
    for(i = 645; !found && i < N - 3; i++)
    {
diff --git a/C/p049.c b/C/p049.c
index 842d314..5d354e7 100644
--- a/C/p049.c
+++ b/C/p049.c
@@ -18,7 +18,11 @@ int main(int argc, char **argv)
 
    clock_gettime(CLOCK_MONOTONIC, &start);
 
-   primes = sieve(N);
+   if((primes = sieve(N)) == NULL)
+   {
+      fprintf(stderr, "Error! Sieve function returned NULL\n");
+      return 1;
+   }
 
    for(i = 1489; i < N && !found; i++)
    {
diff --git a/C/p050.c b/C/p050.c
index f7e9aba..aea0414 100644
--- a/C/p050.c
+++ b/C/p050.c
@@ -15,7 +15,11 @@ int main(int argc, char **argv)
 
    clock_gettime(CLOCK_MONOTONIC, &start);
 
-   primes = sieve(N);
+   if((primes = sieve(N)) == NULL)
+   {
+      fprintf(stderr, "Error! Sieve function returned NULL\n");
+      return 1;
+   }
 
    for(i = 2; i < N; i++)
    {