交集运算

如果数组 1 = { 1,2,3,4,6}

  数组 2 = {1,2,5,6,7 }

那么，数组1和数组2的交集是

Array1 ^ array 2 = {1,2,3,4,6} ^ {1,2,5,6,7}
                 = {1,2,6}

一组共同的元素被称为交集。

交集的逻辑如下 −

k=0;
for(i=0;i<size1;i++){
   for(j=0;j<size2;j++){
      if(a[i]==b[j]){
         intersection[k]=a[i];
         k++;
      }
   }
}

程序

以下是执行两个数组交集操作的C程序 −

演示

#include<stdio.h>
int removerepeated(int size,int a[]);
void sort(int size,int a[]);
main(){
   int i,size1,size2,size,j=0,k,intersectionsize;
   printf("Enter size of an array1</p><p>");
   scanf("%d",&size1);
   printf("Enter size of an array2</p><p>");
   scanf("%d",&size2);
   int a[size1],b[size2],uni[size1+size2];
   if(size1<size2){
      intersectionsize=size1;
   }else if(size1>size2){
      intersectionsize=size2;
   }else{
      intersectionsize=size1;
   }
   int intersection[intersectionsize];
   printf("Enter numbers for array 1</p><p>");
   for(i=0;i<size1;i++){
      scanf("%d",&a[i]);
   }
   printf("Enter numbers for array 2</p><p>");
   for(i=0;i<size2;i++){
      scanf("%d",&b[i]);
   }
   //Intersection starts
   k=0;
   for(i=0;i<size1;i++){
      for(j=0;j<size2;j++){
         if(a[i]==b[j]){
            intersection[k]=a[i];
            k++;
         }
      }
   }
   //Sorting
   sort(k,intersection);
   //Removing
   size=removerepeated(k,intersection);
   printf("Array after intersection</p><p>");
   if(size>0){
      for(i=0;i<size;i++){
         printf("%d</p><p>",intersection[i]);
      }
   }else{
      printf("No intersection</p><p>");
   }
}
int removerepeated(int size,int a[]){
   int i,j,k;
   for(i=0;i<size;i++){
      for(j=i+1;j<size;){
         if(a[i]==a[j]){
            for(k=j;k<size;k++){
               a[k]=a[k+1];
            }
            size--;
         }else{
            j++;
         }
      }
   }
   return(size);
}
void sort(int size,int a[]){
   int i,j,temp;
   for(i=0;i<size;i++){
      for(j=i+1;j<size;j++){
         if(a[i]>a[j]){
            temp=a[i];
            a[i]=a[j];
            a[j]=temp;
         }
      }
   }
}

输出

当上述程序被执行时，它产生以下结果 −

Enter size of an array1
5
Enter size of an array2
2
Enter numbers for array 1
4
5
6
7
8
Enter numbers for array 2
4
1
Array after intersection
4