Leetcode 166 Fraction to Recurring Decimal
Leetcode 166 Fraction to Recurring Decimal
triplebee
发布于 2018-01-12 14:48:06
发布于 2018-01-12 14:48:06
Given two integers representing the numerator and denominator of a fraction, return the fraction in string format.
If the fractional part is repeating, enclose the repeating part in parentheses.
For example,
- Given numerator = 1, denominator = 2, return "0.5".
- Given numerator = 2, denominator = 1, return "2".
- Given numerator = 2, denominator = 3, return "0.(6)".
分数转小数。
模拟小数除法，狂WA不止，还是不够细！
1. 考虑结果正负，
2. 全部转为正数，因为负数会不便于中间处理，
3.用map保存余数和商对应位置的关系，出现重复余数直接插入括号结束.
4. 用longlong，INT_MIN变成正值会炸
5. 我用stringstream进行数转string，看到有人这么做：
res += to_string(integral); 学到了
class Solution {
public:
string fractionToDecimal(int numerator1, int denominator1) {
long long numerator = numerator1>0 ? numerator1 : -(long long)numerator1;
long long denominator = denominator1>0 ? denominator1 : -(long long)denominator1;
string res;
stringstream s;
s << numerator / denominator;
s >> res;
if((long long)numerator1 * denominator1 < 0) res='-'+res;
numerator = numerator % denominator;
if(numerator)
{
res+=".";
unordered_map<int, int> mp;
while(numerator)
{
if(mp.find(numerator) != mp.end())
{
res.insert(mp[numerator], 1, '(');
res += ")";
break;
}
mp[numerator] = res.size();
numerator*=10;
int digit = numerator / denominator;
numerator%=denominator;
string add;
stringstream ss;
ss << digit;
ss >> add;
res += add;
}
}
return res;
}
};本文参与 腾讯云自媒体分享计划，分享自作者个人站点/博客。
原始发表：2017-01-09 ，如有侵权请联系 cloudcommunity@tencent.com 删除
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