void merget(int *a, int length, int *b, int lengthB) {
    if (a == nil || b == nil || length <=0 || lengthB <=0) return;
    int originalOfLengthA = 0;
    int i = 0;
    while (a[i] != 0) {
        originalOfLengthA ++;
        i ++;
    }
    //空間不夠
    if (originalOfLengthA + lengthB > length) {
        return;
    }

    int indexOfNew = originalOfLengthA + lengthB - 1;
    int indexOfOriginalA = originalOfLengthA - 1;
    int indexOfOriginalB = lengthB - 1;

    while (indexOfOriginalA >=0 && indexOfOriginalB >=0) {
        if (a[indexOfOriginalA] > b[indexOfOriginalB]) {
            a[indexOfNew] = a[indexOfOriginalA--];
        } else {
            a[indexOfNew] = b[indexOfOriginalB--];
        }
        indexOfNew--;
    }

    while (indexOfOriginalA >=0) {
        a[indexOfNew--] = a[indexOfOriginalA--];
    }
    while (indexOfOriginalB >=0) {
        a[indexOfNew--] = b[indexOfOriginalB--];
    }

    for (int i = 0; i < length; i ++) {
        NSLog(@"%d", a[i]);
    }

}

int main(int argc, const char * argv[]) {
    @autoreleasepool {
        int a[] = {1,3,5,7,9,11,0,0,0,0,0,0,0,0,0};
        int b[] = {1,2,4,6,8};
        merget(a, 15, b, 5);
    }
    return 0;
}