5.9 LeetCode

class Solution {
    public String fractionToDecimal(int numerator, int denominator) {
        long n=Math.abs((long)numerator),d=Math.abs((long)denominator);
        StringBuilder sb=new StringBuilder();
        if((long)numerator * (long)denominator < 0)
            sb.append("-");
        sb.append(String.valueOf(n/d));
        n%=d;
        if(n==0) return sb.toString();
        sb.append(".");
        int t=2;
        while(t<n){
            if((n/t)*t==n &&(d/t)*t==d)
            {
                n/=t;d/=t;
            }
            else t++;
        }
        //System.out.println(n+"   "+d);
        long index=sb.length();
        HashMap<Long,Long> m=new HashMap<>();
        while(n!=0){
            if(m.containsKey(n)){
                sb.insert(Integer.parseInt(m.get(n).toString()),"(");
                sb.append(")");
                break;
            }
            m.put(n,index);
            n*=10;
            sb.append(n/d);
            n=n%d;
            index++;
        }
        return sb.toString();
        
    }

}

class Solution {
    public int getSum(int a, int b) {
        return b == 0 ? a : getSum(a^b,(a&b)<<1); 
    }
}