C语言:判断Armstrong数(阿姆斯壮数)

问题:Armstrong 数，就是n位数的各位数的n次方之和等于该数，如：

153=1³⁺⁵3+3^3
1634=1⁴⁺⁶4+3⁴⁺⁴4

代码1:

#include <stdio.h>
int main()
{
int number, originalNumber, remainder, result = 0;

printf("输入三位数: ");
scanf("%d", &number);

originalNumber = number;

while (originalNumber != 0)
{
    remainder = originalNumber%10;
    result += remainder*remainder*remainder;
    originalNumber /= 10;
}

if(result == number)
    printf("%d 是 Armstrong 数",number);
else
    printf("%d 不是 Armstrong 数",number);

return 0;
}

运行结果:

输入三位数: 371
371 是 Armstrong 

代码2:两数之间的 Armstrong 数

#include <stdio.h>
#include <math.h>

int main()
{
int low, high, i, temp1, temp2, remainder, n = 0, result = 0;

printf("输入两个整数: ");
scanf("%d %d", &low, &high);
printf("%d 和 %d 之间的 Armstrong 数为: ", low, high);

for(i = low + 1; i < high; ++i)
{
    temp2 = i;
    temp1 = i;

    // 计算
    while (temp1 != 0)
    {
        temp1 /= 10;
        ++n;
    }
    
    while (temp2 != 0)
    {
        remainder = temp2 % 10;
        result += pow(remainder, n);
        temp2 /= 10;
    }

    if (result == i) {
        printf("%d ", i);
    }

    n = 0;
    result = 0;

}
return 0;
}

运行结果:

输入两个整数: 100 1000
100 和 1000 之间的 Armstrong 数为: 153 370 371 407

代码3:使用函数判断Armstrong 数

#include <stdio.h>
#include <math.h>

int checkPrimeNumber(int n);
int checkArmstrongNumber(int n);

int main()
{
int n, flag;

printf("输入正整数: ");
scanf("%d", &n);

// 检测素数
flag = checkPrimeNumber(n);
if (flag == 1)
    printf("%d 是素数。\n", n);
else
    printf("%d 不是素数\n", n);

// 检测 Armstrong 数
flag = checkArmstrongNumber(n);
if (flag == 1)
    printf("%d 是 Armstrong 数。", n);
else
    printf("%d 不是 Armstrong 数。",n);
return 0;
}

int checkPrimeNumber(int n)
{
int i, flag = 1;

for(i=2; i<=n/2; ++i)
{

// 非素数条件
    if(n%i == 0)
    {
        flag = 0;
        break;
    }
}
return flag;
}

int checkArmstrongNumber(int number)
{
int originalNumber, remainder, result = 0, n = 0, flag;

originalNumber = number;

while (originalNumber != 0)
{
    originalNumber /= 10;
    ++n;
}

originalNumber = number;

while (originalNumber != 0)
{
    remainder = originalNumber%10;
    result += pow(remainder, n);
    originalNumber /= 10;
}

// 判断条件
if(result == number)
    flag = 1;
else
    flag = 0;

return flag;
}

运行结果:

输入正整数: 371
371 不是素数
371 是 Armstrong 数。

参考代码:

#include<stdio.h>
long long power(long long x,int y)
{
long long sum = 1;
while(y--)
{
    sum *= x;
}
return sum;
}

int check_arm(long long n)
{
long long temp,sum = 0,remainder,count = 0;
temp = n;
while(temp*10/10 != 0)
{
    temp /= 10;
    ++count;
}
temp = n;
while(temp*10/10 != 0)
{
    sum += power(temp%10,count);
    temp /= 10;
}
if(n == sum)
{
    return 1;
}
else
{
    return 0;
}
}
int main()
{
long long temp,n,result,a,b,i;
int flag;
printf("Please enter a number:\n");
scanf("%lld",&n);
result = check_arm(n);
if(result == 1)
{
    printf("Yes, it's an Armstrong number.\n\n");
}
else
{
    printf("No, it isn't an Armstrong number.\n\n");
}
printf("Please enter two numbers as an interregional,seperated by a space.\n");
scanf("%lld %lld",&a,&b);
flag = 1;
if(a == b)
{
    printf("That is no an valid interregional.\n");
    flag = 0;
}
else if(a > b)
{
    temp = a;
    a = b;
    b = temp;
}
if(flag == 1)
{
    printf("Armstrong number(s) between %lld and %lld is(are):\n",a,b);
    for(i = a;i<=b;i++)
    {
        if(check_arm(i) == 1)
        {
            printf("%lld ",i);
        }
    }
}
return 0;
}

2>

#include <stdio.h>
int main(){
int low,high;
scanf("%d %d",&low,&high);    
while(low<=high){
    if(arm(low)==1)    printf("%d \t",low);
    low++;
}

}

int arm(int a){

int b=0,c=0,e=0; //初始化 
c=a;
while(c>0){
    if(c%10>=0) e++;
    c =c/10;
}    
c=a;
while(a>0){
    b=b+pow(a%10,e);
    a=a/10;
}
if(c==b) return 1;
else return 0;
}