In this post, we are going to solve the Multiply Strings Leetcode Solution problem of Leetcode. This Leetcode problem is done in many programming languages like C++, Java, and Python.
Problem
Given two non-negative integers num1 and num2 represented as strings, return the product of num1 and num2, also represented as a string.
Note: You must not use any built–in BigInteger library or convert the inputs to integer directly.
Example 1:
Input: num1 = "2", num2 = "3" Output: "6"
Example 2:
Input: num1 = "123", num2 = "456" Output: "56088"
Constraints:
1 <= num1.length, num2.length <= 200num1Â andÂnum2Â consist of digits only.- BothÂ
num1Â andÂnum2Â do not contain any leading zero, except the numberÂ0Â itself.
Now, let’s see the leetcode solution of Multiply Strings Leetcode Solution.
Multiply Strings Leetcode Solution in Python
class Solution:
def multiply(self, num1: str, num2: str) -> str:
s = [0] * (len(num1) + len(num2))
for i in reversed(range(len(num1))):
for j in reversed(range(len(num2))):
mult = int(num1[i]) * int(num2[j])
summ = mult + s[i + j + 1]
s[i + j] += summ // 10
s[i + j + 1] = summ % 10
for i, c in enumerate(s):
if c != 0:
break
return ''.join(map(str, s[i:]))
Multiply Strings Leetcode Solution in CPP
class Solution {
public:
string multiply(string num1, string num2) {
string s(num1.length() + num2.length(), '0');
for (int i = num1.length() - 1; i >= 0; --i)
for (int j = num2.length() - 1; j >= 0; --j) {
const int mult = (num1[i] - '0') * (num2[j] - '0');
const int sum = mult + (s[i + j + 1] - '0');
s[i + j] += sum / 10;
s[i + j + 1] = '0' + sum % 10;
}
const int i = s.find_first_not_of('0');
return i == -1 ? "0" : s.substr(i);
}
};
Multiply Strings Leetcode Solution in Java
class Solution {
public String multiply(String num1, String num2) {
final int m = num1.length();
final int n = num2.length();
StringBuilder sb = new StringBuilder();
int[] pos = new int[m + n];
for (int i = m - 1; i >= 0; --i)
for (int j = n - 1; j >= 0; --j) {
final int multiply = (num1.charAt(i) - '0') * (num2.charAt(j) - '0');
final int sum = multiply + pos[i + j + 1];
pos[i + j] += sum / 10;
pos[i + j + 1] = sum % 10;
}
for (final int p : pos)
if (p > 0 || sb.length() > 0)
sb.append(p);
return sb.length() == 0 ? "0" : sb.toString();
}
}
Note: This problem Multiply Strings is generated by Leetcode but the solution is provided by Chase2learn This tutorial is only for Educational and Learning purposes.
