Golang | Leetcode Golang题解之第306题累加数

题目：

题解：

func stringAdd(x, y string) string {res := []byte{}carry, cur := 0, 0for x != "" || y != "" || carry != 0 {cur = carryif x != "" {cur += int(x[len(x)-1] - '0')x = x[:len(x)-1]}if y != "" {cur += int(y[len(y)-1] - '0')y = y[:len(y)-1]}carry = cur / 10cur %= 10res = append(res, byte(cur)+'0')}for i, n := 0, len(res); i < n/2; i++ {res[i], res[n-1-i] = res[n-1-i], res[i]}return string(res)
}func valid(num string, secondStart, secondEnd int) bool {n := len(num)firstStart, firstEnd := 0, secondStart-1for secondEnd <= n-1 {third := stringAdd(num[firstStart:firstEnd+1], num[secondStart:secondEnd+1])thirdStart := secondEnd + 1thirdEnd := secondEnd + len(third)if thirdEnd >= n || num[thirdStart:thirdEnd+1] != third {break}if thirdEnd == n-1 {return true}firstStart, firstEnd = secondStart, secondEndsecondStart, secondEnd = thirdStart, thirdEnd}return false
}func isAdditiveNumber(num string) bool {n := len(num)for secondStart := 1; secondStart < n-1; secondStart++ {if num[0] == '0' && secondStart != 1 {break}for secondEnd := secondStart; secondEnd < n-1; secondEnd++ {if num[secondStart] == '0' && secondStart != secondEnd {break}if valid(num, secondStart, secondEnd) {return true}}}return false
}