301.Remove Invalid Parentheses.go

package leetcode

var (
res []string
mpmap[string]int
nint
lengthint
maxScoreint
strstring
)

funcremoveInvalidParentheses(sstring) []string {
lmoves, rmoves, lcnt, rcnt:=0, 0, 0, 0
for_, v:=ranges {
ifv=='(' {
lmoves++
lcnt++
 } elseifv==')' {
iflmoves!=0 {
lmoves--
 } else {
rmoves++
 }
rcnt++
 }
 }
n=len(s)
length=n-lmoves-rmoves
res= []string{}
mp=make(map[string]int)
maxScore=min(lcnt, rcnt)
str=s
backtrace(0, "", lmoves, rmoves, 0)
returnres
}

funcbacktrace(iint, curstring, lmovesint, rmovesint, scoreint) {
iflmoves<0||rmoves<0||score<0||score>maxScore {
return
 }
iflmoves==0&&rmoves==0 {
iflen(cur) ==length {
if_, ok:=mp[cur]; !ok {
res=append(res, cur)
mp[cur] =1
 }
return
 }
 }
ifi==n {
return
 }
ifstr[i] =='(' {
backtrace(i+1, cur+string('('), lmoves, rmoves, score+1)
backtrace(i+1, cur, lmoves-1, rmoves, score)
 } elseifstr[i] ==')' {
backtrace(i+1, cur+string(')'), lmoves, rmoves, score-1)
backtrace(i+1, cur, lmoves, rmoves-1, score)
 } else {
backtrace(i+1, cur+string(str[i]), lmoves, rmoves, score)
 }
}

funcmin(a, bint) int {
ifa<b {
returna
 }
returnb
}