如果N是一个富余数,并且所有它的适当除数都是不足数,则将数字N称为原始富余数。
前几个原始大量数字是:
20, 70, 88, 104, 272, 304………
检查N是否为原始数量
给定数字N ,任务是查找此数字是否为原始大量数字。
例子:
Input: N = 20
Output: YES
Explanation:
Sum of 20’s proper divisors is – 1 + 2 + 4 + 5 + 10 = 22 > 20,
So, 20 is an abundant number.
The proper divisors of 1, 2, 4, 5 and 10 are0, 1, 3, 1 and 8 respectively,
Each of these numbers is a deficient number
Therefore, 20 is a primitive abundant number.
Input: N = 17
Output: No
方法:
- 检查该数字是否为一个充裕的数字,即,由sum(N)表示的数字的所有适当除数的总和大于数字N的值
- 如果数量不多,则返回false,否则请执行以下操作
- 检查N的所有适当除数是否为不足数,即,由divisorsSum(n)表示的数字的所有除数的总和小于数字N的值的两倍。
- 如果以上两个条件都满足,则打印“是”,否则打印“否” 。
下面是上述方法的实现:
C++
// C++ implementation of the above
// approach
#include
using namespace std;
// Function to sum of divisors
int getSum(int n)
{
int sum = 0;
// Note that this loop
// runs till square root of N
for (int i = 1; i <= sqrt(n); i++) {
if (n % i == 0) {
// If divisors are equal,
// take only one of them
if (n / i == i)
sum = sum + i;
else // Otherwise take both
{
sum = sum + i;
sum = sum + (n / i);
}
}
}
return sum;
}
// Function to check Abundant Number
bool checkAbundant(int n)
{
// Return true if sum
// of divisors is greater
// than N.
return (getSum(n) - n > n);
}
// Function to check Deficient Number
bool isDeficient(int n)
{
// Check if sum(n) < 2 * n
return (getSum(n) < (2 * n));
}
// Function to check all proper divisors
// of N is deficient number or not
bool checkPrimitiveAbundant(int num)
{
// if number itself is not abundant
// retuen false
if (!checkAbundant(num)) {
return false;
}
// find all divisors which divides 'num'
for (int i = 2; i <= sqrt(num); i++) {
// if 'i' is divisor of 'num'
if (num % i == 0 && i != num) {
// if both divisors are same then add
// it only once else add both
if (i * i == num) {
if (!isDeficient(i)) {
return false;
}
}
else if (!isDeficient(i) || !isDeficient(num / i)) {
return false;
}
}
}
return true;
}
// Driver Code
int main()
{
int n = 20;
if (checkPrimitiveAbundant(n)) {
cout << "Yes";
}
else {
cout << "No";
}
return 0;
}
Java
// Java implementation of the above
// approach
class GFG{
// Function to sum of divisors
static int getSum(int n)
{
int sum = 0;
// Note that this loop runs
// till square root of N
for(int i = 1; i <= Math.sqrt(n); i++)
{
if (n % i == 0)
{
// If divisors are equal,
// take only one of them
if (n / i == i)
sum = sum + i;
// Otherwise take both
else
{
sum = sum + i;
sum = sum + (n / i);
}
}
}
return sum;
}
// Function to check Abundant Number
static boolean checkAbundant(int n)
{
// Return true if sum
// of divisors is greater
// than N.
return (getSum(n) - n > n);
}
// Function to check Deficient Number
static boolean isDeficient(int n)
{
// Check if sum(n) < 2 * n
return (getSum(n) < (2 * n));
}
// Function to check all proper divisors
// of N is deficient number or not
static boolean checkPrimitiveAbundant(int num)
{
// If number itself is not abundant
// retuen false
if (!checkAbundant(num))
{
return false;
}
// Find all divisors which divides 'num'
for(int i = 2; i <= Math.sqrt(num); i++)
{
// if 'i' is divisor of 'num'
if (num % i == 0 && i != num)
{
// if both divisors are same then
// add it only once else add both
if (i * i == num)
{
if (!isDeficient(i))
{
return false;
}
}
else if (!isDeficient(i) ||
!isDeficient(num / i))
{
return false;
}
}
}
return true;
}
// Driver Code
public static void main(String[] args)
{
int n = 20;
if (checkPrimitiveAbundant(n))
{
System.out.print("Yes");
}
else
{
System.out.print("No");
}
}
}
// This code is contributed by Ritik Bansal
Python3
# Python3 implementation of the above
# approach
import math
# Function to sum of divisors
def getSum(n):
sum = 0
# Note that this loop
# runs till square root of N
for i in range(1, int(math.sqrt(n) + 1)):
if (n % i == 0):
# If divisors are equal,
# take only one of them
if (n // i == i):
sum = sum + i
else:
# Otherwise take both
sum = sum + i
sum = sum + (n // i)
return sum
# Function to check Abundant Number
def checkAbundant(n):
# Return True if sum
# of divisors is greater
# than N.
if (getSum(n) - n > n):
return True
return False
# Function to check Deficient Number
def isDeficient(n):
# Check if sum(n) < 2 * n
if (getSum(n) < (2 * n)):
return True
return False
# Function to check all proper divisors
# of N is deficient number or not
def checkPrimitiveAbundant(num):
# if number itself is not abundant
# retuen False
if not checkAbundant(num):
return False
# find all divisors which divides 'num'
for i in range(2, int(math.sqrt(num) + 1)):
# if 'i' is divisor of 'num'
if (num % i == 0 and i != num):
# if both divisors are same then add
# it only once else add both
if (i * i == num):
if (not isDeficient(i)):
return False
elif (not isDeficient(i) or
not isDeficient(num // i)):
return False
return True
# Driver Code
n = 20
if (checkPrimitiveAbundant(n)):
print("Yes")
else:
print("No")
# This code is contributed by shubhamsingh10
C#
// C# implementation of the above
// approach
using System;
class GFG{
// Function to sum of divisors
static int getSum(int n)
{
int sum = 0;
// Note that this loop runs
// till square root of N
for(int i = 1; i <= Math.Sqrt(n); i++)
{
if (n % i == 0)
{
// If divisors are equal,
// take only one of them
if (n / i == i)
sum = sum + i;
// Otherwise take both
else
{
sum = sum + i;
sum = sum + (n / i);
}
}
}
return sum;
}
// Function to check Abundant Number
static bool checkAbundant(int n)
{
// Return true if sum
// of divisors is greater
// than N.
return (getSum(n) - n > n);
}
// Function to check Deficient Number
static bool isDeficient(int n)
{
// Check if sum(n) < 2 * n
return (getSum(n) < (2 * n));
}
// Function to check all proper divisors
// of N is deficient number or not
static bool checkPrimitiveAbundant(int num)
{
// If number itself is not abundant
// retuen false
if (!checkAbundant(num))
{
return false;
}
// Find all divisors which divides 'num'
for(int i = 2; i <= Math.Sqrt(num); i++)
{
// If 'i' is divisor of 'num'
if (num % i == 0 && i != num)
{
// If both divisors are same then
// add it only once else add both
if (i * i == num)
{
if (!isDeficient(i))
{
return false;
}
}
else if (!isDeficient(i) ||
!isDeficient(num / i))
{
return false;
}
}
}
return true;
}
// Driver Code
public static void Main()
{
int n = 20;
if (checkPrimitiveAbundant(n))
{
Console.Write("Yes");
}
else
{
Console.Write("No");
}
}
}
// This code is contributed by Code_Mech
Javascript
输出:
Yes
参考: https : //en.wikipedia.org/wiki/Primitive_abundant_number