diff --git a/src/checker.c b/src/checker.c
index 8a05fbf..6d47d16 100644
--- a/src/checker.c
+++ b/src/checker.c
@@ -13,6 +13,7 @@
 #include "push_swap.h"
 #include <unistd.h>
 #include <stdlib.h>
+#include <unistd.h>
 
 void	execute_move(const char *move, t_state *state)
 {
@@ -43,8 +44,8 @@ int	main(int argc, char *argv[])
 	t_state	*state;
 	char	*move;
 
-	if (!initialise_state(&state))
-		return (1);
+	if (!initialise_state(&state) || argc == 1)
+		return (ft_putstr_fd("Error\n", STDERR_FILENO), 1);
 	while (argc-- > 1)
 	{
 		if (!new_element(&(state->a), argv[argc]))
diff --git a/src/push_swap.c b/src/push_swap.c
index daf32b2..4d2ef78 100644
--- a/src/push_swap.c
+++ b/src/push_swap.c
@@ -12,21 +12,23 @@
 
 #include "libft.h"
 #include "push_swap.h"
+#include <unistd.h>
+
 
 int	main(int argc, char *argv[])
 {
 	t_state	*state;
 
 	state = NULL;
-	if (!initialise_state(&state))
-		return (1);
+	if (!initialise_state(&state) || argc == 1)
+		return (ft_putstr_fd("Error\n", STDERR_FILENO), 1);
 	while (argc-- > 1)
 	{
 		if (!new_element(&(state->a), argv[argc]))
 			return (error(state));
-		if (has_duplicates(state->a))
-			return (error(state));
 	}
+	if (has_duplicates(state->a))
+		return (error(state));
 	if (ft_lstsize(state->a) <= 1 || is_sorted(state->a))
 		return (0);
 	sortmore(state);
diff --git a/tester.sh b/tester.sh
index a548d62..a63fc47 100755
--- a/tester.sh
+++ b/tester.sh
@@ -1,65 +1,266 @@
 #!/bin/bash
 
 # This script is used to test the program
+GREEN='\033[0;32m'
+RED='\033[0;31m'
+NC='\033[0m'
+BOLD='\033[1m'
+
 
 run_test_case() {
-	# echo "Test case $1"
-	MAX=0
-	MIN=10000000
-	AVG=0
-	ITER=$2
-	N=$1
-	MAX_ARGS=""
-	for i in $(seq 1 $ITER)
-	do
-		ARG=$(seq -1000 1000 | shuf -n $N)
-		OPS=$(./push_swap $ARG | wc -l)
-		OK=$(./push_swap $ARG | ./checker $ARG)
-		if [ $OPS -gt $MAX ]
-		then
-			MAX_ARGS="Max: $OPS | $(echo $ARG | tr -d '\n')"
-			MAX=$OPS
-		fi
-		if [ $OPS -lt $MIN ]
-		then
-			MIN=$OPS
-		fi
-		AVG=$((AVG + OPS))
-		if [ $OK != "OK" ]
-		then
-			echo "================================"
-			echo "Error"
-			echo "Args: $ARG"
-			echo "Ops: $OPS"
-			echo "Checker: $OK"
-			echo "================================"
-			return
-		fi
-	done
-	AVG=$((AVG / ITER))
-	# echo -e "$1,\t$AVG,\t$MAX,\t$MIN"
-	echo "List size: $1 Iterations: $ITER avg: $AVG max: $MAX min: $MIN"
-	# echo "Max: $MAX"
-	# echo "Min: $MIN"
-	# echo "Average: $AVG"
-	# echo "--------------------------------"
-	# echo "Max Args: $MAX_ARGS"
-	# echo "--------------------------------"
-	# echo ""
+    # echo "Test case $1"
+    MAX=0
+    MIN=10000000
+    AVG=0
+    ITER=$2
+    N=$1
+    MAX_ARGS=""
+    ABOVE_5500_COUNT=0
 
+    # Create a temporary directory to store outputs
+    TMP_DIR=$(mktemp -d)
+
+    # Function to run a single test iteration
+    run_iteration() {
+        local iter=$1
+        local ARG=$(seq -1000 1000 | shuf -n $N)
+        local OPS=$(./push_swap $ARG | wc -l | tr -d '[:space:]')
+        local OK=$(./push_swap $ARG | ./checker $ARG | tr -d '[:space:]')
+
+        echo "$OPS" > "$TMP_DIR/ops_$iter"
+        echo "$ARG" > "$TMP_DIR/arg_$iter"
+        echo "$OK" > "$TMP_DIR/ok_$iter"
+    }
+
+    export -f run_iteration
+    export TMP_DIR MAX MIN MAX_ARGS AVG N
+
+    # Run the iterations in parallel
+    seq 1 $ITER | xargs -n 1 -P 8 bash -c 'run_iteration "$@"' _
+
+    # Process results
+    for file in $TMP_DIR/ops_*; do
+        if [ -f "$file" ]; then
+            local iter=$(basename $file | cut -d'_' -f2)
+            local OPS=$(cat "$file")
+            local ARG=$(cat "$TMP_DIR/arg_$iter")
+            local OK=$(cat "$TMP_DIR/ok_$iter")
+            AVG=$((AVG + OPS))
+
+            if [ "$OPS" -gt "$MAX" ]; then
+                MAX=$OPS
+                MAX_ARGS="Max: $OPS | $(echo $ARG | tr -d '\n')"
+            fi
+
+            if [ "$OPS" -lt "$MIN" ]; then
+                MIN=$OPS
+            fi
+
+            if [ "$OPS" -gt 5500 ]; then
+                ABOVE_5500_COUNT=$((ABOVE_5500_COUNT + 1))
+            fi
+
+            if [ "$OK" != "OK" ]; then
+                echo "================================"
+                echo "Error"
+                echo "Args: $ARG"
+                echo "Ops: $OPS"
+                echo "Checker: $OK"
+                echo "================================"
+            fi
+        fi
+    done
+
+    AVG=$((AVG / ITER))
+	echo -e "Testing $BOLD$N elements $ITER times:$NC max:$GREEN $MAX$NC min:$RED $MIN$NC avg:$AVG"
+    # echo "Iterations: $ITER"
+    # echo "Max: $MAX"
+    # echo "Min: $MIN"
+    # echo "Average: $AVG"
+    # echo "--------------------------------"
+    # echo "Max Args: $MAX_ARGS"
+    # echo "--------------------------------"
+    # if [ "$N" -eq 500 ]; then
+    #     echo "Number of tests with OPS > 5500: $ABOVE_5500_COUNT"
+    #     echo "--------------------------------"
+    # fi
+    # echo ""
+
+    # Clean up
+    rm -rf "$TMP_DIR"
 }
 
-run_test_case 1 10
-run_test_case 2 10
-run_test_case 3 10
-run_test_case 4 10
-run_test_case 5 10
-run_test_case 10 10
-run_test_case 20 10
-run_test_case 50 10
-run_test_case 100 10
-run_test_case 200 10
-run_test_case 500 10
-
+
+# Test push_swap with non-numeric arguments
+NON_NUMERIC_ARGS="a b c"
+NON_NUMERIC_OUTPUT=$(./push_swap $NON_NUMERIC_ARGS 2>&1 >/dev/null)
+if [ "$NON_NUMERIC_OUTPUT" == "Error" ]; then
+    echo -e "${GREEN}Non-numeric argument test passed${NC}"
+else
+    echo -e "${RED}Non-numeric argument test failed${NC}"
+fi
+
+# Test checker with non-numeric arguments
+NON_NUMERIC_OUTPUT=$(./checker $NON_NUMERIC_ARGS 2>&1 >/dev/null)
+if [ "$NON_NUMERIC_OUTPUT" == "Error" ]; then
+	echo -e "${GREEN}Non-numeric argument test passed${NC}"
+else
+	echo -e "${RED}Non-numeric argument test failed${NC}"
+fi
+
+# Test push_swap with duplicate arguments
+DUPLICATE_ARGS="1 1 2 3"
+DUPLICATE_OUTPUT=$(./push_swap $DUPLICATE_ARGS 2>&1 >/dev/null)
+if [ "$DUPLICATE_OUTPUT" == "Error" ]; then
+	echo -e "${GREEN}Duplicate argument test passed${NC}"
+else
+	echo -e "${RED}Duplicate argument test failed${NC}"
+fi
+
+# Test checker with duplicate arguments
+DUPLICATE_OUTPUT=$(./checker $DUPLICATE_ARGS 2>&1 >/dev/null)
+if [ "$DUPLICATE_OUTPUT" == "Error" ]; then
+	echo -e "${GREEN}Duplicate argument test passed${NC}"
+else
+	echo -e "${RED}Duplicate argument test failed${NC}"
+fi
+
+# Test push_swap with empty arguments
+EMPTY_OUTPUT=$(./push_swap 2>&1 >/dev/null)
+if [ "$EMPTY_OUTPUT" == "Error" ]; then
+	echo -e "${GREEN}Empty argument test passed${NC}"
+else
+	echo -e "${RED}Empty argument test failed${NC}"
+fi
+
+# Test checker with empty arguments
+EMPTY_OUTPUT=$(./checker 2>&1 >/dev/null)
+if [ "$EMPTY_OUTPUT" == "Error" ]; then
+	echo -e "${GREEN}Empty argument test passed${NC}"
+else
+	echo -e "${RED}Empty argument test failed${NC}"
+fi
+
+# Test push_swap with invalid arguments
+INVALID_ARGS="1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 a"
+INVALID_OUTPUT=$(./push_swap $INVALID_ARGS 2>&1 >/dev/null)
+if [ "$INVALID_OUTPUT" == "Error" ]; then
+	echo -e "${GREEN}Invalid argument test passed${NC}"
+else
+	echo -e "${RED}Invalid argument test failed${NC}"
+fi
+
+# Test checker with invalid arguments
+INVALID_OUTPUT=$(./checker $INVALID_ARGS 2>&1 >/dev/null)
+if [ "$INVALID_OUTPUT" == "Error" ]; then
+	echo -e "${GREEN}Invalid argument test passed${NC}"
+else
+	echo -e "${RED}Invalid argument test failed${NC}"
+fi
+
+# Test push_swap with valid arguments
+VALID_ARGS="1 2 3 4 5 6 7 8 9 10 11 12 13 14 15"
+VALID_OUTPUT=$(./push_swap $VALID_ARGS 2>&1 >/dev/null)
+if [ "$VALID_OUTPUT" != "Error" ]; then
+	echo -e "${GREEN}Valid argument test passed${NC}"
+else
+	echo -e "${RED}Valid argument test failed${NC}"
+fi
+
+# Test checker with valid arguments
+VALID_OUTPUT=$(./push_swap $VALID_ARGS | ./checker $VALID_ARGS)
+if [ "$VALID_OUTPUT" == "OK" ]; then
+	echo -e "${GREEN}Valid argument test passed${NC}"
+else
+	echo -e "${RED}Valid argument test failed${NC}"
+fi
+
+#Run push_swap with non numeric parameters. The program must display "Error".
+OUTPUT=$(./push_swap a b c)
+if [ "$OUTPUT" == "Error" ]; then
+	echo -e "${GREEN}Non-numeric argument test passed${NC}"
+else
+	echo -e "${RED}Non-numeric argument test failed${NC}"
+fi
+
+#Run push_swap with a duplicate numeric parameter. The program must display "Error".
+OUTPUT=$(./push_swap 1 1 2 3)
+if [ "$OUTPUT" == "Error" ]; then
+	echo -e "${GREEN}Duplicate argument test passed${NC}"
+else
+	echo -e "${RED}Duplicate argument test failed${NC}"
+fi
+
+#Run push_swap with only numeric parameters including one greater than MAXINT. The program must display "Error".
+OUTPUT=$(./push_swap 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 999999999999999)
+if [ "$OUTPUT" == "Error" ]; then
+	echo -e "${GREEN}Invalid argument test passed${NC}"
+else
+	echo -e "${RED}Invalid argument test failed${NC}"
+fi
+
+#Run push_swap without any parameters. The program must not display anything and give the prompt back.
+OUTPUT=$(./push_swap)
+if [ "$OUTPUT" == "" ]; then
+	echo -e "${GREEN}Empty argument test passed${NC}"
+else
+	echo -e "${RED}Empty argument test failed${NC}"
+fi
+
+#Run the following command "$>./push_swap 42". The program should display nothing (0 instruction).
+OUTPUT=$(./push_swap 42)
+if [ "$OUTPUT" == "" ]; then
+	echo -e "${GREEN}Single argument test passed${NC}"
+else
+	echo -e "${RED}Single argument test failed${NC}"
+fi
+
+#Run the following command "$>./push_swap 2 3". The program should display nothing (0 instruction).
+OUTPUT=$(./push_swap 2 3)
+if [ "$OUTPUT" == "" ]; then
+	echo -e "${GREEN}Two arguments test passed${NC}"
+else
+	echo -e "${RED}Two arguments test failed${NC}"
+fi
+
+#Run the following command "$>./push_swap 0 1 2 3". The program should display nothing (0 instruction).
+OUTPUT=$(./push_swap 0 1 2 3)
+if [ "$OUTPUT" == "" ]; then
+	echo -e "${GREEN}Four arguments test passed${NC}"
+else
+	echo -e "${RED}Four arguments test failed${NC}"
+fi
+
+#Run the following command "$>./push_swap 0 1 2 3 4 5 6 7 8 9". The program should display nothing (0 instruction).
+OUTPUT=$(./push_swap 0 1 2 3 4 5 6 7 8 9)
+if [ "$OUTPUT" == "" ]; then
+	echo -e "${GREEN}Ten arguments test passed${NC}"
+else
+	echo -e "${RED}Ten arguments test failed${NC}"
+fi
+
+#Run the following command "$>./push_swap 'Between 0 and 9 randomly sorted values chosen>'. The program should display nothing (0 instruction).
+OUTPUT=$(./push_swap 11 22 33 44 55 66 77 88 99)
+if [ "$OUTPUT" == "" ]; then
+	echo -e "${GREEN}Ten arguments test passed${NC}"
+else
+	echo -e "${RED}Ten arguments test failed${NC}"
+fi
+
+#Run "$>ARG="2 1 0"; ./push_swap $ARG | ./checker_OS $ARG". Check that the checker program displays "OK" and that the size of the list of instructions from push_swap is 2 OR 3. Otherwise the test fails.
+OUTPUT=$(ARG="2 1 0"; ./push_swap $ARG | ./checker $ARG)
+if [ "$OUTPUT" == "OK" ]; then
+	echo -e "${GREEN}Three arguments test passed${NC}"
+else
+	echo -e "${RED}Three arguments test failed${NC}"
+fi
+
+#Run "$>ARG="1 5 2 4 3"; ./push_swap $ARG | ./checker_OS $ARG". Check that the checker program displays "OK" and that the size of the list of instructions from push_swap is 12. Otherwise the test fails.
+OUTPUT=$(ARG="1 5 2 4 3"; ./push_swap $ARG | ./checker $ARG)
+if [ "$OUTPUT" == "OK" ]; then
+	echo -e "${GREEN}Five arguments test passed${NC}"
+else
+	echo -e "${RED}Five arguments test failed${NC}"
+fi