#leetcode#Fraction to Recurring Decimal

public class Solution {
    public String fractionToDecimal(int numerator, int denominator) {
        if(numerator == 0)
            return "0";
        StringBuilder sb = new StringBuilder();
        if((numerator > 0) ^ (denominator > 0))
            sb.append('-');
        long num = Math.abs((long)numerator);
        long den = Math.abs((long)denominator);
        sb.append(num / den);
        if(num % den == 0)
            return sb.toString();
        sb.append(".");
        Map<Long, Integer> map = new HashMap<>();
        while(num != 0){
            long remainder = num % den;
            if(!map.containsKey(remainder)){
                map.put(remainder, sb.length());
                remainder *= 10;
                sb.append(remainder / den);
                num = remainder % den;
            }else{
                sb.insert(map.get(remainder), "(");
                sb.append(")");
                break;
            }
        }
        
        return sb.toString();
    }
}

版权声明：本文为博主原创文章，未经博主允许不得转载。