给定一个大的n,我们需要检查它是否可以被37整除。如果可以被37整除,则输出true,否则返回False。
例子:
Input : 74
Output : True
Input : 73
Output : False
Input : 8955795758 (10 digit number)
Output : True
A R位数m中数字的形式是(AR-1 AR-2 … .a2 A1 A0)为整除37当且仅当一系列的数字(A2 A1 A0)+(A5 A4 A3)+(A8的总和a7 a6)+…可除以37。括号内的数字三元组表示数字形式的3位数。
The given number n can be written as a sum of powers of 1000 as follows.
n = (a2 a1 a0) + (a5 a4 a3)*1000 + (a8 a7 a6)*(1000*1000) +….
As 1000 = (1)(mod 37), 1000 as per congruence relation.
For a positive integer n, two numbers a and b are said to be congruent modulo n, if their difference
(a – b) is an integer multiple of n (that is, if there is an integer k such that a – b = kn). This congruence relation is typically considered when a and b are integers, and is denoted
Hence we can write:
n = { (a2a1a0) + (a5a4a3)* (1) + (a8a7a6)* (1)*(1)+…..}(mod 37),
Thus n is divisible by 37 if and if only if the series is divisible by 37.
例子:
Input : 8955795758 (10 digit number)
Output : True
Explanation:
We express the number in terms of
triplets of digits as follows.
(008)(955)(795)(758)
Now, 758 + 795 + 955 + 8 = 2516
For 2516, the triplets will be:
(002)(516)
Now 516 + 2 = 518 which is divisible
by 37. Hence the number is divisible
by 37.
Input : 189710809179199 (15 digit number)
Output : False
一种简单而有效的方法是采用字符串形式的输入(如果需要,通过在数字的左边加0来使其长度为3 * m),然后必须将数字从右到左以3为单位添加,直到它变成一个3位数的数字组成一个系列。计算系列的总和。如果系列的总和中包含3个以上的数字,请再次递归调用此函数。
最后检查结果总和是否可被37整除。
这是检查37除数的程序实现。
C++
// CPP program for checking divisibility by 37
// function divisible37 which returns True if
// number is divisible by 37 otherwise False
#include
using namespace std;
int divisibleby37(string n){
int l = n.length();
if (n == "0")
return 0;
// Append required 0's at the beginning
if (l % 3 == 1){
n = "00"+ n;
l += 2;
}
else if (l % 3 == 2){
n = "0"+ n;
l += 1;
}
int gSum = 0;
while (l != 0){
// group saves 3-digit group
string group = n.substr(l - 3, l);
l = l - 3;
int gvalue = (group[0] - '0') * 100 +
(group[1] - '0') * 10 +
(group[2] - '0') * 1;
// add the series
gSum = gSum + gvalue;
}
// if sum of series gSum has minimum 4
// digits in it, then again recursive
// call divisibleby37 function
if (gSum >= 1000)
return (divisibleby37(to_string(gSum)));
else
return (gSum % 37 == 0);
}
// drive program to test the above function
int main(){
string s="8955795758";
if (divisibleby37(s))
cout<<"True";
else
cout<<"False";
return 0;
}
// This code is contributed by Prerna Saini
Java
// Java program for checking
// divisibility by 37
class GFG
{
// function divisible37 which
// returns True if number is
// divisible by 37 otherwise False
static int divisibleby37(String n1)
{
int l = n1.length();
if (n1 == "0")
return 0;
// Append required 0's
// at the beginning
if (l % 3 == 1)
{
n1 = "00"+ n1;
l += 2;
}
else if (l % 3 == 2)
{
n1 = "0"+ n1;
l += 1;
}
char[] n= n1.toCharArray();
int gSum = 0;
while (l != 0)
{
// group saves 3-digit group
int gvalue;
if(l == 2)
gvalue = ((int)n[(l - 2)] - 48) * 100 +
((int)n[(l - 1)] - 48) * 10;
else if(l == 1)
gvalue = ((int)n[(l - 1)] - 48) * 100;
else
gvalue = ((int)n[(l - 3)] - 48) * 100 +
((int)n[(l - 2)] - 48) * 10 +
((int)n[(l - 1)] - 48) * 1;
l = l - 3;
// add the series
gSum = gSum + gvalue;
}
// if sum of series gSum has minimum 4
// digits in it, then again recursive
// call divisibleby37 function
if (gSum >= 1000)
return (divisibleby37(String.valueOf(gSum)));
else
return (gSum % 37 == 0) ? 1 : 0;
}
// Driver Code
public static void main(String[] args)
{
String s="8955795758";
if (divisibleby37(s) == 1)
System.out.println("True");
else
System.out.println("False");
}
}
// This code is contributed by mits
Python3
# Python code for checking divisibility by 37
# function divisible37 which returns True if
# number is divisible by 37 otherwise False
def divisibleby37(n):
l = len(n)
if (n == 0):
return True
# Append required 0's at the beginning
if (l%3 == 1):
n = "00"+ n
l += 2
elif (l%3 == 2):
n = "0"+ n
l += 1
gSum = 0
while (l != 0):
# group saves 3-digit group
group = int(n[l-3:l])
l = l-3
# add the series
gSum = gSum + group
# if sum of series gSum has minimum 4
# digits in it, then again recursive
# call divisibleby37 function
if (gSum >= 1000):
return(divisibleby37(str(gSum)))
else:
return (gSum%37==0)
# Driver method to test the above function
print(divisibleby37("8955795758"))
C#
// C# program for checking
// divisibility by 37
using System;
class GFG
{
// function divisible37 which
// returns True if number is
// divisible by 37 otherwise False
static int divisibleby37(string n)
{
int l = n.Length;
if (n == "0")
return 0;
// Append required 0's
// at the beginning
if (l % 3 == 1)
{
n = "00"+ n;
l += 2;
}
else if (l % 3 == 2)
{
n = "0"+ n;
l += 1;
}
int gSum = 0;
while (l != 0)
{
// group saves 3-digit group
int gvalue;
if(l == 2)
gvalue = ((int)n[(l - 2)] - 48) * 100 +
((int)n[(l - 1)] - 48) * 10;
else if(l == 1)
gvalue = ((int)n[(l - 1)] - 48) * 100;
else
gvalue = ((int)n[(l - 3)] - 48) * 100 +
((int)n[(l - 2)] - 48) * 10 +
((int)n[(l - 1)] - 48) * 1;
l = l - 3;
// add the series
gSum = gSum + gvalue;
}
// if sum of series gSum has minimum 4
// digits in it, then again recursive
// call divisibleby37 function
if (gSum >= 1000)
return (divisibleby37(gSum.ToString()));
else
return (gSum % 37 == 0) ? 1 : 0;
}
// Driver Code
public static void Main()
{
string s="8955795758";
if (divisibleby37(s) == 1)
Console.WriteLine("True");
else
Console.WriteLine("False");
}
}
// This code is contributed by mits
PHP
= 1000)
return (divisibleby37((string)($gSum)));
else
return ($gSum % 37 == 0);
}
// Driver code
$s = "8955795758";
if (divisibleby37($s))
echo "True";
else
echo "False";
// This code is contributed
// by mits
?>
Javascript
输出:
True