#include<stdio.h>
int main(){
  int a[10],b[10],c[10],i;
  printf("Enter First array->");
  for(i=0;i<10;i++)
  scanf("%d",&a[i]);
  printf("\nEnter Second array->");
  for(i=0;i<10;i++)
            scanf("%d",&b[i]);
  printf("Arrays before swapping");
  printf("\nFirst array->");
  for(i=0;i<10;i++){
            printf("%d",a[i]);
  }
  printf("\nSecond array->");
  for(i=0;i<10;i++){
            printf("%d",b[i]);
  }
  for(i=0;i<10;i++){
            //write any swapping technique
            c[i]=a[i];
            a[i]=b[i];
            b[i]=c[i];
  }
  printf("\nArrays after swapping");
  printf("\nFirst array->");
  for(i=0;i<10;i++){
            printf("%d",a[i]);
  }
  printf("\nSecond array->");
  for(i=0;i<10;i++){
            printf("%d",b[i]);
  }
  return 0;
}

#include<stdio.h>
int main(){
  int i=0,j=0,k=0;
  char str1[20],str2[20],temp[20];
  puts("Enter first string");
  gets(str1);
  puts("Enter second string");
  gets(str2);
  printf("Before swaping the strings are\n");
  puts(str1);
  puts(str2);
  while(str1[i]!='\0'){
             temp[j++]=str1[i++];
  }
  temp[j]='\0';
  i=0,j=0;
  while(str2[i]!='\0'){
              str1[j++]=str2[i++];
  }
  str1[j]='\0';
  i=0,j=0;
  while(temp[i]!='\0'){
              str2[j++]=temp[i++];
  }
  str2[j]='\0';
  printf("After swaping the strings are\n");
  puts(str1);
  puts(str2);
  return 0;
}

#include<stdio.h>

int main(){

    long int decimalNumber,remainder,quotient;

    int binaryNumber[100],i=1,j;

    printf("Enter any decimal number: ");

    scanf("%ld",&decimalNumber);

    quotient = decimalNumber;

    while(quotient!=0){

         binaryNumber[i++]= quotient % 2;

         quotient = quotient / 2;
    }

    printf("Equivalent binary value of decimal number %d: ",decimalNumber);

    for(j = i -1 ;j> 0;j--)

         printf("%d",binaryNumber[j]);

    return 0;
}
Sample output:
Enter any decimal number: 50
Equivalent binary value of decimal number 50: 110010

#include<stdio.h>

int main(){

  long int decimalNumber,remainder,quotient;
  int octalNumber[100],i=1,j;

  printf("Enter any decimal number: ");
  scanf("%ld",&decimalNumber);

  quotient = decimalNumber;

  while(quotient!=0){
      octalNumber[i++]= quotient % 8;
      quotient = quotient / 8;
  }

  printf("Equivalent octal value of decimal number %d: ",decimalNumber);
  for(j = i -1 ;j> 0;j--)
      printf("%d",octalNumber[j]);

  return 0;
}
Sample output:
Enter any decimal number: 50
Equivalent octal value of decimal number 50: 62

#include<stdio.h>
int main(){

  long int decimalNumber;

  printf("Enter any decimal number : ");
  scanf("%d",&decimalNumber);

  printf("Equivalent octal number is: %o",decimalNumber);

  return 0;
}
Sample output:
Enter any decimal number: 25
Equivalent octal number is: 31