public class OneDigitDifference {
 
    public int getSmallest(int N) {
        if(N == 0)
            return 1;
        int[] is = new int[10];
        for(int i = 0; i < 10; i++, N /= 10)
            is[i] = N % 10;
        for(int i = 9; i >= 0; i--)
            if(is[i] > 0) {
                is[i] = 0;
                break;
            }
        int ret = 0;
        for(int i = 9; i >= 0; i--)
            ret = ret * 10 + is[i];
        return ret;
    }
}

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