给定两个大数字作为字符串，找出一个是否是另一个的幂。例如 ：
例子：
Input : a = "374747", b = "52627712618930723"
Output : YES
Explanation : 374747^3 = 52627712618930723
Input : a = "2", b = "4099"
Output : NO
先决条件：将两个大数字相乘以字符串表示该方法很简单。首先，找到两个字符串较小的一个，然后将其与自身相乘，直到等于或大于较大的字符串。如果它们相等，则返回true，否则返回false。
下面是上述方法的实现
C++
// CPP program to check if one number is
// power of other
#include
using namespace std;
bool isGreaterThanEqualTo(string s1, string s2)
{
if (s1.size() > s2.size())
return true;
return (s1 == s2);
}
string multiply(string s1, string s2)
{
int n = s1.size();
int m = s2.size();
vector result(n + m, 0);
// Multiply the numbers. It multiplies
// each digit of second string to each
// digit of first and stores the result.
for (int i = n - 1; i >= 0; i--)
for (int j = m - 1; j >= 0; j--)
result[i + j + 1] +=
(s1[i] - '0') * (s2[j] - '0');
// If the digit exceeds 9, add the
// cumulative carry to previous digit.
int size = result.size();
for (int i = size - 1; i > 0; i--) {
if (result[i] >= 10) {
result[i - 1] += result[i] / 10;
result[i] = result[i] % 10;
}
}
int i = 0;
while (i < size && result[i] == 0)
i++;
// if all zeroes, return "0".
if (i == size)
return "0";
string temp;
// Remove starting zeroes.
while (i < size) {
temp += (result[i] + '0');
i++;
}
return temp;
}
// Removes Extra zeroes from front of a string.
string removeLeadingZeores(string s)
{
int n = s.size();
int i = 0;
while (i < n && s[i] == '0')
i++;
if (i == n)
return "0";
string temp;
while (i < n)
temp += s[i++];
return temp;
}
bool isPower(string s1, string s2)
{
// Make sure there are no leading zeroes
// in the string.
s1 = removeLeadingZeores(s1);
s2 = removeLeadingZeores(s2);
if (s1 == "0" || s2 == "0")
return false;
if (s1 == "1" && s2 == "1")
return true;
if (s1 == "1" || s2 == "1")
return true;
// Making sure that s1 is smaller.
// If it is greater, we recur we
// reversed parameters.
if (s1.size() > s2.size())
return isPower(s2, s1);
string temp = s1;
while (!isGreaterThanEqualTo(s1, s2))
s1 = multiply(s1, temp);
return s1 == s2;
}
int main()
{
string s1 = "374747", s2 = "52627712618930723";
cout << (isPower(s1, s2) ? "YES\n" : "NO\n");
s1 = "4099", s2 = "2";
cout << (isPower(s1, s2) ? "YES\n" : "NO\n");
return 0;
} Java
// Java program to check if one number is
// power of other
import java.util.*;
class new_file
{
static boolean isGreaterThanEqual(String s1,
String s2)
{
if (s1.length() > s2.length())
return true;
if (s1.compareTo(s2) == 0)
return true;
return false;
}
static String multiply(String s1, String s2)
{
int n = s1.length();
int m = s2.length();
int[] result = new int[n + m];
// Multiply the numbers. It multiplies
// each digit of second string to each
// digit of first and stores the result.
for (int i = n - 1; i >= 0; i--)
for (int j = m - 1; j >= 0; j--)
result[i + j + 1] += (s1.charAt(i) - '0') *
(s2.charAt(j) - '0');
// If the digit exceeds 9, add the
// cumulative carry to previous digit.
int size = result.length;
for (int i = size - 1; i > 0; i--)
{
if (result[i] >= 10)
{
result[i - 1] += result[i] / 10;
result[i] = result[i] % 10;
}
}
int i = 0;
while (i < size && result[i] == 0)
i++;
// if all zeroes, return "0".
if (i == size)
return "0";
String temp = "";
// Remove starting zeroes.
while (i < size)
{
temp += Integer.toString(result[i]);
i++;
}
return temp;
}
// Removes Extra zeroes from front of a string.
static String removeLeadingZeores(String s)
{
int n = s.length();
int i = 0;
while (i < n && s.charAt(i) == '0')
i++;
if (i == n)
return "0";
String temp = "";
while (i < n)
{
temp += s.charAt(i);
i++;
}
return temp;
}
static boolean isPower(String s1, String s2)
{
// Make sure there are no leading zeroes
// in the string.
s1 = removeLeadingZeores(s1);
s2 = removeLeadingZeores(s2);
if (s1 == "0" || s2 == "0")
return false;
if (s1 == "1" && s2 == "1")
return true;
if (s1 == "1" || s2 == "1")
return true;
// Making sure that s1 is smaller.
// If it is greater, we recur we
// reversed parameters.
if (s1.length() > s2.length())
return isPower(s2, s1);
String temp = new String(s1);
while (!isGreaterThanEqual(s1, s2))
s1 = multiply(s1, temp);
if (s1.compareTo(s2) == 0)
return true;
return false;
}
// Driver Code
public static void main(String[] args)
{
String s1 = "374747", s2 = "52627712618930723";
if (isPower(s1, s2))
System.out.println("Yes");
else
System.out.println("No");
s1 = "4099";
s2 = "2";
if (isPower(s1, s2))
System.out.println("Yes");
else
System.out.println("No");
}
}
// This code is contributed by
// sanjeev2552Python3
# Python3 program to check if one
# number is a power of other
def isGreaterThanEqualTo(s1, s2):
if len(s1) > len(s2):
return True
return s1 == s2
def multiply(s1, s2):
n, m = len(s1), len(s2)
result = [0] * (n + m)
# Multiply the numbers. It multiplies
# each digit of second string to each
# digit of first and stores the result.
for i in range(n - 1, -1, -1):
for j in range(m - 1, -1, -1):
result[i + j + 1] += (int(s1[i]) *
int(s2[j]))
# If the digit exceeds 9, add the
# cumulative carry to previous digit.
size = len(result)
for i in range(size - 1, 0, -1):
if result[i] >= 10:
result[i - 1] += result[i] // 10
result[i] = result[i] % 10
i = 0
while i < size and result[i] == 0:
i += 1
# If all zeroes, return "0".
if i == size:
return "0"
temp = ""
# Remove starting zeroes.
while i < size:
temp += str(result[i])
i += 1
return temp
# Removes Extra zeroes from front of a string.
def removeLeadingZeores(s):
n, i = len(s), 0
while i < n and s[i] == '0':
i += 1
if i == n:
return "0"
temp = ""
while i < n:
temp += s[i]
i += 1
return temp
def isPower(s1, s2):
# Make sure there are no leading
# zeroes in the string.
s1 = removeLeadingZeores(s1)
s2 = removeLeadingZeores(s2)
if s1 == "0" or s2 == "0":
return False
if s1 == "1" and s2 == "1":
return True
if s1 == "1" and s2 == "1":
return True
# Making sure that s1 is smaller.
# If it is greater, we recur we
# reversed parameters.
if len(s1) > len(s2):
return isPower(s2, s1)
temp = s1
while not isGreaterThanEqualTo(s1, s2):
s1 = multiply(s1, temp)
return s1 == s2
# Driver Code
if __name__ == "__main__":
s1, s2 = "374747", "52627712618930723"
if isPower(s1, s2):
print("YES")
else:
print("NO")
s1, s2 = "4099", "2"
if isPower(s1, s2):
print("YES")
else:
print("NO")
# This code is contributed by Rituraj JainC#
// C# program to check if one number is
// power of other
using System;
public class new_file
{
static bool isGreaterThanEqual(String s1,
String s2)
{
if (s1.Length > s2.Length)
return true;
if (s1.CompareTo(s2) == 0)
return true;
return false;
}
static String multiply(String s1, String s2)
{
int n = s1.Length;
int m = s2.Length;
int i = 0;
int[] result = new int[n + m];
// Multiply the numbers. It multiplies
// each digit of second string to each
// digit of first and stores the result.
for (i = n - 1; i >= 0; i--)
for (int j = m - 1; j >= 0; j--)
result[i + j + 1] += (s1[i] - '0') *
(s2[j] - '0');
// If the digit exceeds 9, add the
// cumulative carry to previous digit.
int size = result.Length;
for (i = size - 1; i > 0; i--)
{
if (result[i] >= 10)
{
result[i - 1] += result[i] / 10;
result[i] = result[i] % 10;
}
}
i = 0;
while (i < size && result[i] == 0)
i++;
// if all zeroes, return "0".
if (i == size)
return "0";
String temp = "";
// Remove starting zeroes.
while (i < size)
{
temp += (result[i]).ToString();
i++;
}
return temp;
}
// Removes Extra zeroes from front of a string.
static String removeLeadingZeores(String s)
{
int n = s.Length;
int i = 0;
while (i < n && s[i] == '0')
i++;
if (i == n)
return "0";
String temp = "";
while (i < n)
{
temp += s[i];
i++;
}
return temp;
}
static bool isPower(String s1, String s2)
{
// Make sure there are no leading zeroes
// in the string.
s1 = removeLeadingZeores(s1);
s2 = removeLeadingZeores(s2);
if (s1 == "0" || s2 == "0")
return false;
if (s1 == "1" && s2 == "1")
return true;
if (s1 == "1" || s2 == "1")
return true;
// Making sure that s1 is smaller.
// If it is greater, we recur we
// reversed parameters.
if (s1.Length > s2.Length)
return isPower(s2, s1);
String temp = s1;
while (!isGreaterThanEqual(s1, s2))
s1 = multiply(s1, temp);
if (s1.CompareTo(s2) == 0)
return true;
return false;
}
// Driver Code
public static void Main(String[] args)
{
String s1 = "374747", s2 = "52627712618930723";
if (isPower(s1, s2))
Console.WriteLine("Yes");
else
Console.WriteLine("No");
s1 = "4099";
s2 = "2";
if (isPower(s1, s2))
Console.WriteLine("Yes");
else
Console.WriteLine("No");
}
}
// This code is contributed by Rajput-Ji输出
YES
NO