diff --git a/Arrays/1D Array/solution.c b/Arrays/1D Array/solution.c
new file mode 100644
index 0000000..cc3460a
--- /dev/null
+++ b/Arrays/1D Array/solution.c	
@@ -0,0 +1,11 @@
+#include<stdio.h>
+main()
+{
+    int n,i,m,j,a[100];
+
+    scanf("%d",&n);
+    for(i=0;i<n;++i)
+       scanf("%d",&a[i]);
+    for(i=n-1;i>=0;--i)
+    printf("%d\n",a[i]);   
+}
diff --git a/Arrays/Multi-D Array/solution.c b/Arrays/Multi-D Array/solution.c
new file mode 100644
index 0000000..22a268b
--- /dev/null
+++ b/Arrays/Multi-D Array/solution.c	
@@ -0,0 +1,17 @@
+#include<stdio.h>
+main()
+{
+    int n,i,m,j,a[10][10];
+
+    scanf("%d%d",&n,&m);
+    for(i=0;i<n;++i)
+     for(j=0;j<m;++j)
+       scanf("%d",&a[i][j]);
+    for(i=0;i<m;++i)
+    {
+
+     
+     for(j=0;j<n;++j)
+    printf("%d ",a[j][i]);
+     printf("\n");   
+}}
diff --git a/Hash Tables/Hash Tables/solution.c b/Hash Tables/Hash Tables/solution.c
new file mode 100644
index 0000000..5ee7208
--- /dev/null
+++ b/Hash Tables/Hash Tables/solution.c	
@@ -0,0 +1,20 @@
+#include<stdio.h>
+#include<string.h>
+main()
+{
+    long int n,r,i,q,a[10000];
+    char s[26],h[101][26];
+    scanf("%ld",&n);
+    for(i=0;i<n;++i)
+    {
+        scanf("%ld%s",&r,s);
+        strcpy(h[r%101],s);
+    }
+    scanf("%ld",&q);
+    for(i=0;i<q;++i)
+     
+          scanf("%ld",&a[i]);
+    for(i=0;i<q;++i)    
+      puts(h[a[i]%101]);    
+     
+}
\ No newline at end of file
diff --git a/Queues/Queues/solution.c b/Queues/Queues/solution.c
new file mode 100644
index 0000000..e1cf48b
--- /dev/null
+++ b/Queues/Queues/solution.c
@@ -0,0 +1,60 @@
+
+#include<stdio.h>
+main()
+{
+    int i,n,h,a[100],e,j=-1,k=-1,r[100][2],f=0,fl=0;
+    char p;
+    scanf("%d",&n);
+    for(i=0;i<n;++i)
+    {
+         while((getchar())!='\n');
+         
+         scanf("%c",&p);
+         if(p=='E')
+         {
+         scanf("%d",&e);
+          
+                      a[++j]=e;
+                      r[++k][0]=j-f+1;
+                      r[k][1]=-2;
+                      fl=0;
+                    
+          }
+          else if(p=='D')
+          {
+                      if(j!=-1 && fl!=1) 
+                      {
+                        if(j==f)
+                            fl=1; 
+                        h=a[f++];
+                        r[++k][0]=h;
+                        r[k][1]=j-f+1;
+ 
+                      }         
+                      else{
+                           r[++k][0]=1;
+                           r[k][1]=0; 
+                               
+                      }
+           }
+
+          
+         }
+    
+
+    for(int i=0;i<n;++i)
+    {
+     
+      for(int m=0;m<2;++m)
+         {
+             if(r[i][m]==-2)
+               break;
+             else    
+                printf("%d ",r[i][m]);
+         }
+        printf("\n");  
+    }
+
+
+
+}
diff --git a/Stacks/Stacks/solution.c b/Stacks/Stacks/solution.c
new file mode 100644
index 0000000..f07e744
--- /dev/null
+++ b/Stacks/Stacks/solution.c
@@ -0,0 +1,55 @@
+
+#include<stdio.h>
+main()
+{
+    int i,n,h,a[100],e,j=-1,r[10000],k=0,m=0;
+    char p;
+    scanf("%d",&n);
+    for(i=0;i<n;++i)
+    {
+         while((getchar())!='\n');
+         
+         scanf("%c",&p);
+         if(p=='2')
+         {
+         scanf("%d",&e);
+          
+                      a[++j]=e;
+
+                    
+          }
+          else if(p=='1')
+          {
+            ++m;
+                      if(j!=-1) 
+                      {
+ 
+                        h=a[j--];
+                        r[k++]=h;
+                        
+ 
+                      }         
+                      else{
+                           r[k++]=-1; 
+                                      
+                      }
+           }
+
+          
+         }
+    
+
+    for(int i=0;i<m;++i)
+    {
+    
+             if(r[i]==-1)
+               printf("No food");
+             else    
+                printf("%d ",r[i]);
+        
+        printf("\n");  
+    }
+
+
+
+}
\ No newline at end of file
diff --git a/Trees/Binary Search Tree/solution.c b/Trees/Binary Search Tree/solution.c
new file mode 100644
index 0000000..2f538b5
--- /dev/null
+++ b/Trees/Binary Search Tree/solution.c	
@@ -0,0 +1,81 @@
+#include<stdio.h>
+#include<stdlib.h>
+struct bi
+{
+  struct bi *l,*r;
+  int v;
+}*b,*root,*p,*ptr;
+
+
+void cre(int h)
+{
+  b=(struct bi*)malloc(sizeof(struct bi));
+  b->r=b->l=NULL;
+  b->v=h;
+  p=root;
+  while(p!=NULL)
+  {
+    ptr=p;
+    if(p->v>h)
+       p=p->l;
+    else
+       p=p->r;
+          
+  }
+  if(ptr->l==NULL && ptr->v>h)
+     ptr->l=b;
+  else if(ptr->r==NULL && ptr->v<h)
+     ptr->r=b;   
+}
+
+void pre(struct bi *k)
+{
+   if(k==NULL)
+      return;
+   
+    printf("%d\n",k->v);
+    pre(k->l);
+   
+    pre(k->r);
+   
+}     
+void trav(int q)
+{ 
+p=root;
+  while(p!=NULL)
+    {
+    if(p->v==q)
+      { pre(p);
+      break;}    
+    else if(p->v>q)
+       p=p->l;
+    else
+       p=p->r;
+          
+  }
+  
+   
+}
+
+
+
+main()
+{
+  int n,l,q;
+  scanf("%d",&n);
+  root=(struct bi*)malloc(sizeof(struct bi));
+  root->l=root->r=NULL;
+  root->v=-1;
+  scanf("%d",&l);
+  root->v=l;
+  for(int i=0;i<n-1;++i)
+  {
+     scanf("%d",&l);
+     cre(l);    
+  }
+   scanf("%d",&q);
+  trav(q);
+  
+}
+
+