Given an array of positive and negative integers, re-arrange it so that you have positive integers on one end and negative integers on other

Question

I recently came across a Microsoft Interview Question for Software Engineer.

Given an array of positive and negative integers, re-arrange it so that you

Answer 1

I hope this helps. This one has Time Complexity O(n^2)

#include 

int main() {
    int a[] = {-3, 2, -5, 9, -2, -8, 6, 8, -1, 6};

    int length = (sizeof(a) / sizeof(int));
    int i, j = 0;

    printf("Size of array: %d\n", sizeof(a));

    for (i = 0; i < length; i++) {
        if (i % 2 == 0 && a[i] < 0) {
            for (j = i + 1; j < length; j++) {
                if (a[j] > 0) {
                    int t = a[i];
                    a[i] = a[j];
                    a[j] = t;
                    break;
                }
            }
        } else if (i % 2 == 1 && a[i] > 0) {
            for (j = i + 1; j < length; j++) {
                if (a[j] < 0) {
                    int t = a[i];
                    a[i] = a[j];
                    a[j] = t;
                    break;
                }
            }
        }
    }

    for (i = 0; i < length; i++) {
        printf("Value at %d: %d\n", i, a[i]);
    }

    return 0;
}

EDIT 1 This relies on the fact that numbers greater than zero are always at an even index and numbers less than zero are always at odd index

EDIT 2 Improved the code a little