[BUGFIX] Many issues "If memory allocation fails, then there is a possible null pointer dereference:" fixed.

Author: Gonzalo Diaz

src/lib/exercises/src/hackerrank/warmup/compare_triplets.c

@@ -12,6 +12,9 @@ int *HACKERRANK_WARMUP_compareTriplets(int a_count, const int *a, int b_count,
 
   *result_count = 2;
   int *awards = malloc(sizeof(int) * *result_count);
+  if (awards == NULL) {
+    return NULL;
+  }
 
   awards[0] = 0;
   awards[1] = 0;

src/lib/exercises/src/hackerrank/warmup/mini_max_sum.c

@@ -27,13 +27,20 @@ char *HACKERRANK_WARMUP_miniMaxSumCalculate(int arr_count, const int *arr) {
 
   const int BUFFER_MAX_SIZE = 100;
   char *buffer = malloc(BUFFER_MAX_SIZE * sizeof(char));
+  if (buffer == NULL) {
+    return NULL;
+  }
 
   snprintf(buffer, BUFFER_MAX_SIZE, "%lld %lld", tsum - tmax, tsum - tmin);
   return buffer;
 }
 
 void HACKERRANK_WARMUP_miniMaxSum(int arr_count, const int *arr) {
   char *result = HACKERRANK_WARMUP_miniMaxSumCalculate(arr_count, arr);
+  if (result == NULL) {
+    return;
+  }
+
   printf("%s\n", result);
   free(result);
 }

src/lib/exercises/src/hackerrank/warmup/plus_minus.c

@@ -11,6 +11,9 @@ const int BUFFER_MAX_SIZE = 10;
 
 char *format_result(double number) {
   char *buffer = malloc(BUFFER_MAX_SIZE * sizeof(char));
+  if (buffer == NULL) {
+    return NULL;
+  }
 
   snprintf(buffer, BUFFER_MAX_SIZE, "%0.6lf", number);
   return buffer;
@@ -45,9 +48,16 @@ char **HACKERRANK_WARMUP_plusMinusCalculate(int arr_count, const int *arr) {
 
   int n = 3; // Número de strings (puede ser arbitrario)
   char **answer = malloc(n * sizeof(char *)); // Array de punteros
+  if (answer == NULL) {
+    return NULL;
+  }
 
   for (i = 0; i < n; i++) {
     char *formatted = format_result(results[i]);
+    if (formatted == NULL) {
+      HACKERRANK_WARMUP_freePlusMinus(answer, i);
+      return NULL;
+    }
     answer[i] = formatted;
   }
 
@@ -63,6 +73,9 @@ void HACKERRANK_WARMUP_freePlusMinus(char **plusMinusAnswer, int n) {
 
 void HACKERRANK_WARMUP_plusMinus(int arr_count, const int *arr) {
   char **output = HACKERRANK_WARMUP_plusMinusCalculate(arr_count, arr);
+  if (output == NULL) {
+    return;
+  }
 
   for (int i = 0; i < HACKERRANK_WARMUP_PLUSMINUS_LIMIT_ANSWERS; i++) {
     printf("%s", output[i]);

src/lib/exercises/src/hackerrank/warmup/staircase.c

@@ -10,9 +10,16 @@
 char **HACKERRANK_WARMUP_staircaseCalculate(int n) {
 
   char **answer = malloc(n * sizeof(char *)); // Array of char pointers
+  if (answer == NULL) {
+    return NULL;
+  }
 
   for (int i = 0; i < n; i++) {
     char *line = malloc((n + 1) * sizeof(char)); // Array of char values
+    if (line == NULL) {
+      HACKERRANK_WARMUP_freeStaircase(answer, i);
+      return NULL;
+    }
 
     for (int j = 0; j < n; j++) {
       if (j < n - i - 1) {
@@ -38,6 +45,9 @@ void HACKERRANK_WARMUP_freeStaircase(char **staircase, int n) {
 
 void HACKERRANK_WARMUP_staircase(int n) {
   char **output = HACKERRANK_WARMUP_staircaseCalculate(n);
+  if (output == NULL) {
+    return;
+  }
 
   for (int i = 0; i < n; i++) {
     printf("%s\n", output[i]);

src/lib/exercises/src/hackerrank/warmup/time_conversion.c

@@ -54,6 +54,10 @@ char *HACKERRANK_WARMUP_timeConversion(const char *s) {
   char *conversion =
       malloc((HACKERRANK_WARMUP_SHORT_TIME_FORMAT_SIZE + 1) * sizeof(char));
 
+  if (conversion == NULL) {
+    return NULL;
+  }
+
   for (int i = 0; i < HACKERRANK_WARMUP_SHORT_TIME_FORMAT_SIZE; i++) {
     conversion[i] = s[i];
   }