diff --git a/Arrays/1D Array/solution.c b/Arrays/1D Array/solution.c
new file mode 100644
index 0000000..1eca0ed
--- /dev/null
+++ b/Arrays/1D Array/solution.c	
@@ -0,0 +1,10 @@
+#include<stdio.h>
+void main()
+{
+    int N,i,A[100];
+    scanf("%d",&N);
+    for(i=0;i<N;i++)
+        scanf("%d",&A[i]);
+    while((--N)+1)
+        printf("%d\n",A[N]);
+}
\ No newline at end of file
diff --git a/Arrays/Multi-D Array/solution.c b/Arrays/Multi-D Array/solution.c
new file mode 100644
index 0000000..ad774a5
--- /dev/null
+++ b/Arrays/Multi-D Array/solution.c	
@@ -0,0 +1,20 @@
+#include<stdio.h>
+void main()
+{
+    int j,i,m,n,A[10][10],B[10][10];
+    scanf("%d %d",&m,&n);
+    for(i=0;i<m;i++)
+    for(j=0;j<n;j++)
+    scanf("%d",&A[i][j]);
+
+    for(i=0;i<m;i++)
+    for(j=0;j<n;j++)
+    B[j][i]=A[i][j];
+    
+
+    for(i=0;i<n;i++)
+    {   for(j=1,printf("%d",B[i][0]);j<m;j++)
+        printf(" %d",B[i][j]);
+        printf("\n");
+    }
+}
\ No newline at end of file
diff --git a/Hash Tables/Hash Tables/solution.c b/Hash Tables/Hash Tables/solution.c
new file mode 100644
index 0000000..b84b611
--- /dev/null
+++ b/Hash Tables/Hash Tables/solution.c	
@@ -0,0 +1,28 @@
+#include<stdio.h>
+#include<stdlib.h>
+struct Student
+{
+     int roll;
+     char name[25]
+};
+void main()
+{
+    int q,i,r,N,N1,j;
+    char nam[25];
+    scanf("%d",&N);
+    struct Student *ptr = (struct Student*) malloc (N * sizeof(struct Student));
+    for(i=0;i<N;i++)
+    scanf("%d %s",&(ptr+i)->roll,&(ptr+i)->name);
+    scanf("%d",&q);
+    for(i=0;i<q;i++)
+    {
+        scanf("%d",&N1);
+        for(j=0;j<N;j++)
+        {
+        if ((ptr+j)->roll==N1)
+         {   printf("%s\n",(ptr+j)->name);
+                break;
+         }
+        }
+    }
+}
\ No newline at end of file
diff --git a/Stacks/Stacks/solution.c b/Stacks/Stacks/solution.c
new file mode 100644
index 0000000..88eefcd
--- /dev/null
+++ b/Stacks/Stacks/solution.c
@@ -0,0 +1,25 @@
+#include<stdio.h>
+
+void main()
+{
+    int f,i,N,cus[100000],top=-1;
+    scanf("%d",&N);
+    for(i=0;i<N;i++)
+    {
+        scanf("%d",&f);
+        if(f==1)
+        {
+            if(top<0)
+            printf("No food\n");
+            else
+            {
+                printf("%d\n",cus[top]);
+                top--;
+            }
+        }
+        else
+        {
+            scanf("%d",&cus[++top]);
+        }
+    }
+}
\ No newline at end of file
diff --git a/checker.sh b/checker.sh
new file mode 100755
index 0000000..69e3c40
--- /dev/null
+++ b/checker.sh
@@ -0,0 +1,66 @@
+#!/bin/sh
+# Copyright 2018, Training Cell MEC
+
+CC=cc
+VERSION="0.1"
+
+PROJ_PATH=$(pwd)
+SOL_FILE="solution.c"
+TESTCASE_DIR="tests"
+OUTPUT_DIR=output
+
+HELP_TEXT="Usage: $0 [-c CC ] [-d PATH] [-h] PROBLEM"
+
+PROBLEM=
+
+help() {
+	echo "$HELP_TEXT"
+	exit 0
+}
+
+error_exit() {
+	echo "critical error: $1"
+	exit 1
+}
+
+while [ $# != 0 ]; do
+	case $1 in
+		-h) help ;;
+		-c) CC=$2 ; shift ;;
+		-d) PROJ_PATH=$2 ; shift ;;
+		-*) ;;
+		*) PROBLEM=$1 ;;
+	esac
+	shift
+done
+
+[ -z "$PROBLEM" ] && error_exit "no problem specified"
+
+# scratch directory
+if [ ! -d "${PROJ_PATH}/${OUTPUT_DIR}" ]; then
+	mkdir "${PROJ_PATH}/${OUTPUT_DIR}" ||
+		error_exit "directory creation failed"
+fi
+find "${PROJ_PATH}/${OUTPUT_DIR}/" -maxdepth 1 -type f -delete ||
+	error_exit "directory operation failed"
+
+# build the source
+$CC -o "${PROJ_PATH}/${OUTPUT_DIR}/bin" "${PROJ_PATH}/${PROBLEM}/${SOL_FILE}" ||
+	error_exit "compilation failed"
+
+# verify the output
+for cs in $(find "${PROJ_PATH}/${PROBLEM}/${TESTCASE_DIR}/"\
+	-maxdepth 1 -iname 'in*.txt' -type f -exec basename "{}" \;); do
+	op_n=$(echo $cs | sed 's/in\(.\)\.txt/\1/') # n as in nth test case
+
+	"${PROJ_PATH}/${OUTPUT_DIR}/bin" <"${PROJ_PATH}/${PROBLEM}/${TESTCASE_DIR}/in${op_n}.txt"\
+		>"${PROJ_PATH}/${OUTPUT_DIR}/op${op_n}.txt"
+
+	cat "${PROJ_PATH}/${OUTPUT_DIR}/op${op_n}.txt" | shasum | cut -d ' ' -f 1 |
+		cmp -s -n 40 "${PROJ_PATH}/${PROBLEM}/${TESTCASE_DIR}/op${op_n}_hashed.txt" - &&
+		echo "test case ${op_n} passed" || echo "test case ${op_n} failed"
+done
+
+# cleanup
+rm -r "${PROJ_PATH}/${OUTPUT_DIR}/" ||
+       error_exit "directory operation failed"