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Update karatsuba_algorithm_for_fast_multiplication.cpp

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Swastika Gupta
2021-07-31 15:36:17 +05:30
committed by GitHub
parent 5281b712ff
commit ce51a2fb1c
1 changed files with 9 additions and 6 deletions
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15
divide_and_conquer/karatsuba_algorithm_for_fast_multiplication.cpp
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@@ -39,17 +39,18 @@ std::string addStrings( std::string first, std::string second )
int64_t length = std::max(len1,len2);
if (len1 < len2) // make the string lengths equal
{
for (int64_t i = 0 ; i < len2 - len1 ; i++)
for (int64_t i = 0 ; i < len2 - len1 ; i++) {
first = '0' + first;
}
}
else if (len1 > len2)
{
for (int64_t i = 0 ; i < len1 - len2 ; i++)
for (int64_t i = 0 ; i < len1 - len2 ; i++) {
second = '0' + second;
}
}
int64_t carry = 0;
for (int64_t i = length-1 ; i >= 0 ; i--)
{
for (int64_t i = length-1 ; i >= 0 ; i--) {
int64_t firstBit = first.at(i) - '0';
int64_t secondBit = second.at(i) - '0';
@@ -75,13 +76,15 @@ int64_t karatsuba_algorithm(std::string str1, std::string str2) {
int64_t n = std::max(len1,len2);
if (len1 < len2)
{
for (int64_t i = 0 ; i < len2 - len1 ; i++)
for (int64_t i = 0 ; i < len2 - len1 ; i++) {
str1 = '0' + str1;
}
}
else if (len1 > len2)
{
for (int64_t i = 0 ; i < len1 - len2 ; i++)
for (int64_t i = 0 ; i < len1 - len2 ; i++) {
str2 = '0' + str2;
}
}
if(n==0) return 0;
if(n==1) return (str1[0] - '0')*(str2[0] - '0');