306. Additive Number.go

package leetcode

import (
"strconv"
"strings"
)

// This function controls various combinations as starting points
funcisAdditiveNumber(numstring) bool {
iflen(num) <3 {
returnfalse
 }
forfirstEnd:=0; firstEnd<len(num)/2; firstEnd++ {
ifnum[0] =='0'&&firstEnd>0 {
break
 }
first, _:=strconv.Atoi(num[:firstEnd+1])
forsecondEnd:=firstEnd+1; max(firstEnd, secondEnd-firstEnd) <=len(num)-secondEnd; secondEnd++ {
ifnum[firstEnd+1] =='0'&&secondEnd-firstEnd>1 {
break
 }
second, _:=strconv.Atoi(num[firstEnd+1 : secondEnd+1])
ifrecursiveCheck(num, first, second, secondEnd+1) {
returntrue
 }
 }
 }
returnfalse
}

funcmax(aint, bint) int {
ifa>b {
returna
 }
returnb
}

// Propagate for rest of the string
funcrecursiveCheck(numstring, x1int, x2int, leftint) bool {
ifleft==len(num) {
returntrue
 }
ifstrings.HasPrefix(num[left:], strconv.Itoa(x1+x2)) {
returnrecursiveCheck(num, x2, x1+x2, left+len(strconv.Itoa(x1+x2)))
 }
returnfalse
}