C语言利用递归实现插入排序，选择排序，快速排序，归并排序算法。 要求有注释 ！ 谢谢各位大神！

//InsertionSort
void insertionSort(int a[], int size) {
int i, j, key;

for (i = 0; i < size; i++) {
key = a[i];
j = i-1;
while (j >= 0 && key < a[j]) { //把元素插入到之前的有序元组中
a[j+1] = a[j];
j--;
}
a[j+1] = key;
}
}

//MergeSort
void merge(int a[], int p, int q, int r) { //合并两个子元组
int i, j, k, n1, n2;
int *array1, *array2;
n1 = q - p + 1,
n2 = r - q;

array1 = (int *)calloc(n1+1, sizeof(int));
array2 = (int *)calloc(n2+1, sizeof(int));
if (array1 == NULL || array2 == NULL) {
printf("Error: calloc failed in concat\n");
exit(EXIT_FAILURE);
}
for(i = 0; i < n1; i++)
array1[i] = a[p + i];
for(i = 0; i < n2; i++)
array2[i] = a[q + 1 + i];
array1[n1] = MAXNUMBER;
array2[n2] = MAXNUMBER;
i = 0, j = 0;
for(k = p; k <= r; k++)
if(array1[i] <= array2[j])
a[k] = array1[i++];
else
a[k] = array2[j++];
free(array1);
free(array2);
}

void mergeSort(int a[], int p, int r) {//归并的递归调用
int q;
if (p < r) {
q = (p+r)/2;
mergeSort(a,p,q);
mergeSort(a,q+1,r);
merge(a,p,q,r);
}
}

//QuickSort
int partition(int a[], int p, int r) {//快排的分组函数
int i, j, x, temp;
x = a[r];
i = p - 1;

for (j = p; j < r; j++)
if (x > a[j]) {
temp = a[++i];
a[i] = a[j];
a[j] = temp;
}
temp = a[++i];
a[i] = a[r];
a[r] = temp;

return i;
}

void quickSort(int a[], int p, int r) { //快排
int q;
if (p < r) {
q = partition(a, p, r);
quickSort(a, p, q-1);
quickSort(a, q+1, r);
}
}

//随即版的quickSort
int randomPartition(int a[], int p, int r){

int i, temp;
i = rand();
while( i < p || i > r)
i = rand();
temp = a[i];
a[i] = a[r];
a[r] = temp;
return partition(a,p,r);
}

void randomQuickSort(int a[], int p, int r){
int q;
if(p < r){
q = randomPartition(a,p,r);
randomQuickSort(a,p,q-1);
randomQuickSort(a,q+1,r);
}
}
//BubbleSort();//冒泡排序
void bubbleSort(int a[], int size) {
int i, j, temp;

for (i = size -1; i >= 0; i--)
for (j = 0; j < i; j++)
if (a[j] < a[j+1]) {
temp = a[j];
a[j] = a[j+1];
a[j+1] = temp;
}
}