From d56b443c8d028692dfdfc658fb60ca258a037689 Mon Sep 17 00:00:00 2001
From: pthakare <pranavthakare9@gmail.com>
Date: Sun, 20 Oct 2019 17:32:53 +0530
Subject: [PATCH] relative sorting

---
 relative-sorting/relative_sort.c | 90 ++++++++++++++++++++++++++++++++
 1 file changed, 90 insertions(+)
 create mode 100644 relative-sorting/relative_sort.c

diff --git a/relative-sorting/relative_sort.c b/relative-sorting/relative_sort.c
new file mode 100644
index 0000000..f9630b9
--- /dev/null
+++ b/relative-sorting/relative_sort.c
@@ -0,0 +1,90 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <string.h>
+int compare(const void * a, const void * b){
+     int a1 = *(int *)a;
+     int b1 = *(int *)b;
+     if (a1 < b1) {
+          return -1;
+     }else if (a1 == b1) {
+          return 0;
+     }
+     return 1;
+}
+int binary_first(int arr[],int l,int r,int k){
+     if (l<=r) {
+          int mid = l + (r-l)/2;
+          if (arr[mid] == k && mid >=0 ) {
+               if (mid == 0) {
+                    return mid;
+               }
+               else if (arr[mid] != arr[mid-1]) {
+                    return mid;
+               }else{
+                    int p=mid;
+                    while (p-1 >= 0) {
+                         if (arr[p] != arr[p-1]) {
+                              break;
+                         }
+                         p--;
+                    }
+                    return p;
+               }
+          }
+          else if (arr[mid] > k) {
+               return binary_first(arr,l,mid-1,k);
+          }else{
+               return binary_first(arr,mid+1,r,k);
+          }
+
+     }
+     return -1;
+}
+int sort_relative(int arr[],int arr1[],int n,int n1){
+     int tmp[n],i,j,k,visited[n];
+     memset(visited,0,sizeof(visited));
+     for (i = 0; i < n; i++) {
+          tmp[i] = arr[i];
+     }
+     //for sorting the tmp array
+     qsort(tmp,sizeof(tmp)/sizeof(tmp[0]),sizeof(tmp[0]),compare);
+     // printf("ds=%d\n", binary_first(tmp,0,n,2));
+     for (i = 0,j=0; i < n1 && j < n; i++) {
+          k = binary_first(tmp,0,n,arr1[i]);
+          if (k >= 0) {
+               while (k < n) {
+                    if (tmp[k] != arr1[i] ) {
+                         break;
+                    }
+                    visited[k] = 1;
+                    arr[j++] = tmp[k];
+                    k++;
+               }
+          }
+     }
+     for (k=0; k < n; k++) {
+          if (visited[k] == 0) {
+               arr[j++] = tmp[k];
+          }
+     }
+}
+int main() {
+     int t,i,j,n,n1;
+     scanf("%d",&t );
+     while (t--) {
+          scanf("%d",&n );
+          scanf("%d",&n1 );
+          int arr[n],arr1[n1];
+          for (i = 0; i < n; i++) {
+               scanf("%d",&arr[i] );
+          }for (i = 0; i < n1; i++) {
+               scanf("%d",&arr1[i] );
+          }
+          sort_relative(arr,arr1,n,n1);
+          for (i = 0; i < n; i++) {
+               printf("%d ",arr[i] );
+          }
+          printf("\n");
+     }
+	return 0;
+}