Program 1

#include<stdio.h>
int main(){
    int num,r,sum=0,temp;

    printf("Enter a number: ");
    scanf("%d",&num);

    temp=num;
    while(num!=0){
         r=num%10;
         num=num/10;
         sum=sum+(r*r*r);
    }
    if(sum==temp)
         printf("%d is an Armstrong number",temp);
    else
         printf("%d is not an Armstrong number",temp);

    return 0;
}

Result 1

Enter a number: 153
153 is an Armstrong number

Program 2

#include<stdio.h>
int main(){
    int num,r,sum,temp;
    int min,max;

    printf("Enter the minimum range: ");
    scanf("%d",&min);

    printf("Enter the maximum range: ");
    scanf("%d",&max);

    printf("Armstrong numbers in given range are: ");
    for(num=min;num<=max;num++){
         temp=num;
         sum = 0;

         while(temp!=0){
             r=temp%10;
             temp=temp/10;
             sum=sum+(r*r*r);
         }
         if(sum==num)
             printf("%d ",num);
    }

    return 0;
}

Result 2

Enter the minimum range: 1
Enter the maximum range: 200
Armstrong numbers in given range are: 1 153

Program 3

#include<stdio.h>
int main(){
    int num,r,sum=0,temp;

    printf("Enter a number: ");
    scanf("%d",&num);

    for(temp=num;num!=0;num=num/10){
         r=num%10;
         sum=sum+(r*r*r);
    }
    if(sum==temp)
         printf("%d is an Armstrong number",temp);
    else
         printf("%d is not an Armstrong number",temp);

    return 0;
}

Result 3

Enter a number: 370
370 is an Armstrong number
Logic of Armstrong number in c

Program 4

#include<stdio.h>
int main(){
    int num,r,sum,temp;

    for(num=1;num<=500;num++){
         temp=num;
         sum = 0;

         while(temp!=0){
             r=temp%10;
             temp=temp/10;
             sum=sum+(r*r*r);
         }
         if(sum==num)
             printf("%d ",num);
    }

    return 0;
}

Result 4

1 153 370 371 407