46 lines
753 B
Go
46 lines
753 B
Go
|
package main
|
||
|
|
|
||
|
|
import (
|
||
|
|
"fmt"
|
||
|
|
"regexp"
|
||
|
|
"strconv"
|
||
|
|
)
|
||
|
|
|
||
|
|
func fractionAddition(expression string) string {
|
||
|
|
abs := func(x int) int {
|
||
|
|
return max(-x, x)
|
||
|
|
}
|
||
|
|
gcd := func(x, y int) int {
|
||
|
|
for y != 0 {
|
||
|
|
x, y = y, x%y
|
||
|
|
}
|
||
|
|
return x
|
||
|
|
}
|
||
|
|
NUM_REGEX, _ := regexp.Compile("[+-]?[0-9]+")
|
||
|
|
|
||
|
|
num, denom := 0, 1
|
||
|
|
|
||
|
|
nums := NUM_REGEX.FindAllString(expression, -1)
|
||
|
|
for i := 0; i < len(nums); i += 2 {
|
||
|
|
next_num, ok := strconv.Atoi(nums[i])
|
||
|
|
if ok != nil {
|
||
|
|
panic("failed to parse numerator")
|
||
|
|
}
|
||
|
|
|
||
|
|
next_denom, ok := strconv.Atoi(nums[i+1])
|
||
|
|
if ok != nil {
|
||
|
|
panic("failed to parse denominator")
|
||
|
|
}
|
||
|
|
|
||
|
|
num = num*next_denom + next_num*denom
|
||
|
|
denom *= next_denom
|
||
|
|
}
|
||
|
|
|
||
|
|
d := abs(gcd(num, denom))
|
||
|
|
|
||
|
|
num /= d
|
||
|
|
denom /= d
|
||
|
|
|
||
|
|
return fmt.Sprintf("%d/%d", num, denom)
|
||
|
|
}
|