LeetCode - Algorithms - 66. Plus One

Problem

66. Plus One

Java

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class Solution {
    public int[] plusOne(int[] digits) {
        final int N = digits.length;
        List<Integer> list = new ArrayList<Integer>();
        boolean carry = false;
        int tmp = digits[N - 1] + 1;
        if (tmp < 10) {
            list.add(tmp);
        } else {
            list.add(tmp % 10);
            carry = true;
        }
        if (N >= 2) {
            for (int i = N - 2; i >= 0; i--) {
                tmp = digits[i];
                if (carry)
                    tmp++;
                if (tmp < 10) {
                    carry = false;
                    list.add(tmp);
                } else {
                    carry = true;
                    list.add(tmp % 10);
                }
            }
        }
        if (carry)
            list.add(1);

        final int LEN = list.size();
        int[] a = new int[LEN];
        for (int i = 0; i < LEN; i++) {
            a[LEN - i - 1] = list.get(i).intValue();
        }
        return a;       
    }
}

Submission Detail

  • 109 / 109 test cases passed.
  • Runtime: 1 ms, faster than 17.94% of Java online submissions for Plus One.
  • Memory Usage: 39.9 MB, less than 5.08% of Java online submissions for Plus One.

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class Solution {
    public int[] plusOne(int[] digits) {
        final int N = digits.length;
        List<Integer> list = new ArrayList<Integer>();
        boolean carry = false;
        int tmp = digits[N - 1] + 1;
        if (tmp < 10) {
            list.add(tmp);
        } else {
            list.add(tmp - 10);
            carry = true;
        }
        for (int i = N - 2; i >= 0; i--) {
            tmp = digits[i];
            if (carry)
                tmp++;
            if (tmp < 10) {
                carry = false;
                list.add(tmp);
            } else {
                carry = true;
                list.add(tmp - 10);
            }
        }
        if (carry)
            list.add(1);

        final int LEN = list.size();
        int[] a = new int[LEN];
        for (int i = 0; i < LEN; i++) {
            a[LEN - i - 1] = list.get(i).intValue();
        }
        return a;       
    }
}

Submission Detail

  • 109 / 109 test cases passed.
  • Runtime: 1 ms, faster than 17.94% of Java online submissions for Plus One.
  • Memory Usage: 38.4 MB, less than 20.96% of Java online submissions for Plus One.

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class Solution {
    public int[] plusOne(int[] digits) {
        final int N = digits.length;
        int[] a2 = new int[N];
        boolean carry = false;
        int tmp = digits[N - 1] + 1;
        if (tmp < 10) {
            a2[N - 1] = (tmp);
        } else {
            a2[N - 1] = tmp - 10;
            carry = true;
        }
        for (int i = N - 2; i >= 0; i--) {
            tmp = digits[i];
            if (carry)
                tmp++;
            if (tmp < 10) {
                carry = false;
                a2[i] = tmp;
            } else {
                carry = true;
                a2[i] = tmp - 10;
            }
        }
        if (carry) {
            int[] a1 = new int[N + 1];
            a1[0] = 1;
            System.arraycopy(a2, 0, a1, 1, N);
            return a1;
        } else
            return a2;       
    }
}

Submission Detail

  • 109 / 109 test cases passed.
  • Runtime: 0 ms, faster than 100.00% of Java online submissions for Plus One.
  • Memory Usage: 39.6 MB, less than 8.37% of Java online submissions for Plus One.