C program to print Armstrong numbers from 1 to 500

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C program to print Armstrong numbers from 1 to 500

#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;

}

Output:

1 153 370 371 407

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Algorithm:

Definition according to c programming point of view:

Those numbers which sum of the cube of its digits is equal to that number are known as Armstrong numbers. For example 153 since 1^3 + 5^3 + 3^3 = 1+ 125 + 9 =153

Other Armstrong numbers: 370,371,407 etc.

In general definition:

Those numbers which sum of its digits to power of number of its digits is equal to that number are known as Armstrong numbers.

Example 1: 153

Total digits in 153 is 3

And 1^3 + 5^3 + 3^3 = 1 + 125 + 27 = 153

Example 2: 1634

Total digits in 1634 is 4

And 1^4 + 6^4 + 3^4 +4^4 = 1 + 1296 + 81 + 64 =1634

Examples of Armstrong numbers: 1, 2, 3, 4, 5, 6, 7, 8, 9, 153, 370, 371, 407, 1634, 8208, 9474, 54748, 92727, 93084, 548834, 1741725

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