LeetCode //C - 1317. Convert Integer to the Sum of Two No-Zero Integers

1317. Convert Integer to the Sum of Two No-Zero Integers

No-Zero integer is a positive integer that does not contain any 0 in its decimal representation.

Given an integer n, return a list of two integers a, b where:

• a and b are No-Zero integers.
• a + b = n

The test cases are generated so that there is at least one valid solution. If there are many valid solutions, you can return any of them.

Example 1:

Input: n = 2

Output: 1,1

Explanation: Let a = 1 and b = 1.

Both a and b are no-zero integers, and a + b = 2 = n.

Example 2:

Input: n = 11

Output: 2,9

Explanation: Let a = 2 and b = 9.

Both a and b are no-zero integers, and a + b = 11 = n.

Note that there are other valid answers as 8, 3 that can be accepted.

Constraints:

• 2 < = n < = 10 4 2 <= n <= 10^4 2<=n<=104

From: LeetCode

Link: 1317. Convert Integer to the Sum of Two No-Zero Integers

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Solution:

Ideas:

Try every a from 1 to n - 1, set b = n - a, and return the first pair containing no digit 0.

Code:

#include <stdlib.h>
#include <stdbool.h>

static bool isNoZero(int num) {
    while (num > 0) {
        if (num % 10 == 0) {
            return false;
        }
        num /= 10;
    }
    return true;
}

/**
 * Note: The returned array must be malloced, assume caller calls free().
 */
int* getNoZeroIntegers(int n, int* returnSize) {
    int* answer = malloc(2 * sizeof(int));

    for (int a = 1; a < n; a++) {
        int b = n - a;

        if (isNoZero(a) && isNoZero(b)) {
            answer[0] = a;
            answer[1] = b;
            *returnSize = 2;
            return answer;
        }
    }

    *returnSize = 0;
    free(answer);
    return NULL;
}